HP 3600 v2 Series User manual
HP 3600 v2 Switch Series
Layer 3 - IP Services
Configuration Guide
Part number: 5998-2351
Software version: Release 2108P01
Document version: 6W100-20131130
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Contents
Configuring ARP··························································································································································· 1
Overview············································································································································································1
ARP message format ················································································································································1
ARP operation···························································································································································2
ARP table···································································································································································3
Configuring a static ARP entry·········································································································································3
Configuring the maximum number of dynamic ARP entries for an interface······························································4
Setting the aging timer for dynamic ARP entries ···········································································································4
Enabling dynamic ARP entry check ································································································································5
Configuring ARP quick update ········································································································································5
Configuring multicast ARP················································································································································6
Displaying and maintaining ARP·····································································································································7
ARP configuration examples ············································································································································7
Static ARP entry configuration example·················································································································7
Multicast ARP configuration example·····················································································································8
Configuring gratuitous ARP ·······································································································································11
Overview········································································································································································· 11
Gratuitous ARP packet learning··························································································································· 11
Periodic sending of gratuitous ARP packets ······································································································· 11
Configuration guidelines ··············································································································································· 12
Configuration procedure··············································································································································· 12
Enabling IP conflict notification ···································································································································· 12
Configuring proxy ARP··············································································································································14
Overview········································································································································································· 14
Common proxy ARP·············································································································································· 14
Local proxy ARP····················································································································································· 14
Enabling common proxy ARP ······································································································································· 15
Enabling local proxy ARP·············································································································································· 15
Displaying and maintaining proxy ARP······················································································································· 16
Proxy ARP configuration examples ······························································································································ 16
Common proxy ARP configuration example ······································································································ 16
Local proxy ARP configuration example in case of port isolation ··································································· 17
Local proxy ARP configuration example in super VLAN··················································································· 18
Local proxy ARP configuration example in isolate-user-VLAN·········································································· 19
Configuring ARP snooping········································································································································22
Overview········································································································································································· 22
Configuration procedure··············································································································································· 22
Displaying and maintaining ARP snooping ················································································································ 22
Configuring IP addressing·········································································································································23
Overview········································································································································································· 23
IP address classes·················································································································································· 23
Special IP addresses ············································································································································· 24
Subnetting and masking ······································································································································· 24
Assigning an IP address to an interface ······················································································································ 25
Configuration guidelines ······································································································································ 25
Configuration procedure ······································································································································ 25
Configuration example ········································································································································· 25
ii
Configuring IP unnumbered ·········································································································································· 27
Overview································································································································································ 27
Configuration guidelines ······································································································································ 27
Configuration prerequisites ·································································································································· 27
Configuration procedure ······································································································································ 28
Displaying and maintaining IP addressing ················································································································· 28
DHCP overview ··························································································································································29
DHCP address allocation ·············································································································································· 29
Dynamic IP address allocation process··············································································································· 30
IP address lease extension···································································································································· 30
DHCP message format··················································································································································· 31
DHCP options ································································································································································· 32
Common DHCP options········································································································································ 32
Custom options ······················································································································································ 32
Protocols and standards ················································································································································ 36
Configuring DHCP server ··········································································································································38
Overview········································································································································································· 38
DHCP address pool··············································································································································· 38
IP address allocation sequence···························································································································· 39
DHCP server configuration task list ······························································································································ 39
Configuring an address pool for the DHCP server····································································································· 40
Configuration task list ··········································································································································· 40
Creating a DHCP address pool··························································································································· 40
Configuring address allocation mode for a common address pool ································································ 41
Configuring dynamic address allocation for an extended address pool························································ 43
Configuring a domain name suffix for the client ······························································································· 44
Configuring DNS servers for the client ··············································································································· 44
Configuring WINS servers and NetBIOS node type for the client ·································································· 44
Configuring BIMS server information for the client···························································································· 45
Configuring gateways for the client ···················································································································· 45
Configuring Option 184 parameters for the client with voice service ···························································· 46
Configuring the TFTP server and bootfile name for the client··········································································· 46
Specifying a server's IP address for the DHCP client ························································································ 47
Configuring self-defined DHCP options ·············································································································· 47
Enabling DHCP ······························································································································································ 48
Enabling the DHCP server on an interface·················································································································· 48
Configuration guidelines ······································································································································ 48
Configuration procedure ······································································································································ 49
Applying an extended address pool on an interface ································································································ 49
Configuring the DHCP server security functions ········································································································· 50
Configuration prerequisites ·································································································································· 50
Enabling unauthorized DHCP server detection ·································································································· 50
Configuring IP address conflict detection ··········································································································· 50
Enabling client offline detection ··································································································································· 51
Enabling handling of Option 82·································································································································· 51
Configuration prerequisites ·································································································································· 51
Enabling Option 82 handling······························································································································ 51
Specifying the threshold for sending trap messages·································································································· 52
Configuration prerequisites ·································································································································· 52
Configuration procedure ······································································································································ 52
Setting the DSCP value for DHCP packets ·················································································································· 52
Displaying and maintaining the DHCP server ············································································································ 52
DHCP server configuration examples ·························································································································· 53
iii
Static IP address assignment configuration example························································································· 53
Dynamic IP address assignment configuration example··················································································· 55
Self-defined option configuration example········································································································· 56
Troubleshooting DHCP server configuration ··············································································································· 57
Symptom································································································································································· 57
Analysis ·································································································································································· 57
Solution··································································································································································· 57
Configuring DHCP relay agent ·································································································································58
Overview········································································································································································· 58
Fundamentals························································································································································· 58
DHCP relay agent support for Option 82 ·········································································································· 59
DHCP relay agent configuration task list····················································································································· 60
Enabling DHCP ······························································································································································ 60
Enabling the DHCP relay agent on an interface ········································································································ 60
Correlating a DHCP server group with a relay agent interface················································································ 61
Configuration guidelines ······································································································································ 61
Configuration procedure ······································································································································ 61
Configuring the DHCP relay agent security functions ································································································ 62
Configuring address check ·································································································································· 62
Configuring periodic refresh of dynamic client entries ····················································································· 62
Enabling unauthorized DHCP server detection ·································································································· 63
Enabling DHCP starvation attack protection ······································································································ 63
Enabling offline detection·············································································································································· 64
Configuring the DHCP relay agent to release an IP address ···················································································· 64
Configuring the DHCP relay agent to support Option 82························································································· 65
Configuration prerequisites ·································································································································· 65
Configuration guidelines ······································································································································ 65
Configuration procedure ······································································································································ 65
Setting the DSCP value for DHCP packets ·················································································································· 66
Displaying and maintaining the DHCP relay agent ··································································································· 66
DHCP relay agent configuration examples················································································································· 67
DHCP relay agent configuration example·········································································································· 67
DHCP relay agent Option 82 support configuration example········································································· 68
Troubleshooting DHCP relay agent configuration······································································································ 69
Symptom································································································································································· 69
Analysis ·································································································································································· 69
Solution··································································································································································· 69
Configuring DHCP client ···········································································································································70
Configuration restrictions ·············································································································································· 70
Enabling the DHCP client on an interface··················································································································· 70
Setting the DSCP value for DHCP packets ·················································································································· 70
Displaying and maintaining the DHCP client·············································································································· 71
DHCP client configuration example ····························································································································· 71
Network requirements··········································································································································· 71
Configuration procedure ······································································································································ 71
Verifying the configuration··································································································································· 72
Configuring DHCP snooping·····································································································································74
DHCP snooping functions·············································································································································· 74
Ensuring that DHCP clients obtain IP addresses from authorized DHCP servers············································ 74
Recording IP-to-MAC mappings of DHCP clients ······························································································· 74
Application environment of trusted ports····················································································································· 75
Configuring a trusted port connected to a DHCP server··················································································· 75
Configuring trusted ports in a cascaded network ······································································································ 75
iv
DHCP snooping support for Option 82······················································································································· 76
DHCP snooping configuration task list ························································································································ 77
Configuring DHCP snooping basic functions·············································································································· 77
Configuring DHCP snooping to support Option 82··································································································· 78
Configuring DHCP snooping entries backup ·············································································································· 80
Enabling DHCP starvation attack protection ··············································································································· 81
Enabling DHCP-REQUEST message attack protection ······························································································· 81
Displaying and maintaining DHCP snooping ············································································································· 82
DHCP snooping configuration examples····················································································································· 82
DHCP snooping configuration example ············································································································· 82
DHCP snooping Option 82 support configuration example ············································································ 83
Configuring BOOTP client·········································································································································85
Overview········································································································································································· 85
BOOTP application ··············································································································································· 85
Obtaining an IP address dynamically················································································································· 85
Protocols and standards ······································································································································· 85
Configuration restrictions ·············································································································································· 85
Configuring an interface to dynamically obtain an IP address through BOOTP ···················································· 86
Displaying and maintaining BOOTP client configuration·························································································· 86
BOOTP client configuration example ·························································································································· 86
Network requirements··········································································································································· 86
Configuration procedure ······································································································································ 86
Configuring IPv4 DNS ···············································································································································87
Overview········································································································································································· 87
Static domain name resolution····························································································································· 87
Dynamic domain name resolution······················································································································· 87
DNS proxy ····························································································································································· 88
DNS spoofing ························································································································································ 89
Configuring the IPv4 DNS client ·································································································································· 90
Configuring static domain name resolution········································································································ 90
Configuring dynamic domain name resolution·································································································· 90
Configuring the DNS proxy ·········································································································································· 91
Configuring DNS spoofing ··········································································································································· 92
Setting the DSCP value for DNS packets····················································································································· 92
Specifying the source interface for DNS packets ······································································································· 92
Displaying and maintaining IPv4 DNS························································································································ 93
Static domain name resolution configuration example······························································································ 93
Network requirements··········································································································································· 93
Configuration procedure ······································································································································ 94
Dynamic domain name resolution configuration example ························································································ 94
Network requirements··········································································································································· 94
Configuration procedure ······································································································································ 95
Verifying the configuration··································································································································· 97
DNS proxy configuration example ······························································································································ 97
Network requirements··········································································································································· 97
Configuration procedure ······································································································································ 98
Verifying the configuration··································································································································· 98
Troubleshooting IPv4 DNS configuration ···················································································································· 99
Symptom································································································································································· 99
Solution··································································································································································· 99
Configuring IRDP····················································································································································· 100
Overview·······································································································································································100
Background··························································································································································100
v
Working mechanism···········································································································································100
Concepts·······························································································································································101
Protocols and standards ·····································································································································101
Configuration procedure·············································································································································101
IRDP configuration example········································································································································102
Network requirements·········································································································································102
Configuration procedure ····································································································································103
Verifying the configuration·································································································································104
Optimizing IP performance ···································································································································· 105
Enabling receiving and forwarding of directed broadcasts to a directly connected network·····························105
Enabling receiving of directed broadcasts to a directly connected network················································105
Enabling forwarding of directed broadcasts to a directly connected network·············································105
Configuration example ·······································································································································106
Configuring TCP attributes ··········································································································································106
Configuring TCP path MTU discovery···············································································································106
Configuring the TCP send/receive buffer size ·································································································107
Configuring TCP timers ·······································································································································107
Configuring ICMP to send error packets ···················································································································108
Advantages of sending ICMP error packets·····································································································108
Disadvantages of sending ICMP error packets································································································109
Configuration procedure ····································································································································109
Displaying and maintaining IP performance optimization ······················································································110
Configuring UDP helper·········································································································································· 111
Overview·······································································································································································111
Configuration restrictions and guidelines··················································································································111
Configuration procedure·············································································································································111
Displaying and maintaining UDP helper ···················································································································112
UDP helper configuration example ····························································································································112
Network requirements·········································································································································112
Configuration procedure ····································································································································112
Configuring IPv6 basics·········································································································································· 114
Overview·······································································································································································114
IPv6 features·························································································································································114
IPv6 addresses·····················································································································································115
IPv6 neighbor discovery protocol······················································································································118
IPv6 path MTU discovery····································································································································120
IPv6 transition technologies································································································································121
Protocols and standards ·····································································································································121
IPv6 basics configuration task list·······························································································································122
Configuring basic IPv6 functions································································································································123
Enabling IPv6·······················································································································································123
Configuring an IPv6 global unicast address ····································································································123
Configuring an IPv6 link-local address ·············································································································125
Configure an IPv6 anycast address···················································································································126
Configuring IPv6 ND ···················································································································································127
Configuring a static neighbor entry ··················································································································127
Configuring the maximum number of neighbors dynamically learned ·························································127
Setting the age timer for ND entries in stale state ···························································································128
Configuring parameters related to RA messages ····························································································128
Configuring the maximum number of attempts to send an NS message for DAD·······································131
Configuring ND snooping··································································································································131
Enabling ND proxy ·············································································································································133
Configuring path MTU discovery ·······························································································································135
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Configuring a static path MTU for a specific IPv6 address ············································································135
Configuring the aging time for dynamic path MTUs·······················································································135
Configuring IPv6 TCP properties ································································································································135
Configuring ICMPv6 packet sending·························································································································136
Configuring the maximum ICMPv6 error packets sent in an interval ····························································136
Enabling replying to multicast echo requests ···································································································136
Enabling sending ICMPv6 time exceeded messages······················································································137
Enabling sending ICMPv6 destination unreachable messages······································································137
Displaying and maintaining IPv6 basics configuration····························································································138
IPv6 basics configuration example ····························································································································139
Network requirements·········································································································································139
Configuration procedure ····································································································································140
Verifying the configuration·································································································································141
Troubleshooting IPv6 basics configuration················································································································144
Symptom·······························································································································································144
Solution·································································································································································145
DHCPv6 overview··················································································································································· 146
Hardware compatibility···············································································································································146
Introduction to DHCPv6···············································································································································146
DHCPv6 address/prefix assignment··························································································································146
Rapid assignment involving two messages·······································································································146
Assignment involving four messages·················································································································146
Address/prefix lease renewal ····································································································································147
Configuring stateless DHCPv6····································································································································148
Operation·····························································································································································148
Protocols and standards ··············································································································································149
Configuring DHCPv6 server··································································································································· 150
Overview·······································································································································································150
Concepts·······························································································································································150
Prefix selection process·······································································································································151
DHCPv6 server configuration task list························································································································151
Enabling the DHCPv6 server ······································································································································152
Creating a prefix pool·················································································································································152
Configuring a DHCPv6 address pool························································································································152
Configuration restrictions and guidelines ·········································································································152
Configuration procedure ····································································································································152
Applying the address pool to an interface················································································································153
Setting the DSCP value for DHCPv6 packets ············································································································154
Displaying and maintaining the DHCPv6 server ······································································································154
DHCPv6 server configuration example······················································································································155
Network requirements·········································································································································155
Configuration considerations ·····························································································································155
Configuration procedure ····································································································································155
Verifying the configuration·································································································································156
Configuring DHCPv6 relay agent·························································································································· 158
Overview·······································································································································································158
DHCPv6 relay agent operation ·························································································································158
Configuring the DHCPv6 relay agent························································································································159
Configuration guidelines ····································································································································159
Configuration procedure ····································································································································159
Setting the DSCP value for DHCPv6 packets ············································································································160
Displaying and maintaining the DHCPv6 relay agent·····························································································160
DHCPv6 relay agent configuration example ············································································································160
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Network requirements·········································································································································160
Configuration procedure ····································································································································161
Verifying the configuration·································································································································161
Configuring DHCPv6 client ···································································································································· 163
Overview·······································································································································································163
Configuring the DHCPv6 client···································································································································163
Configuration prerequisites ································································································································163
Configuration guidelines ····································································································································163
Configuration procedure ····································································································································163
Setting the DSCP value for DHCPv6 packets ············································································································163
Displaying and maintaining the DHCPv6 client ·······································································································164
Stateless DHCPv6 configuration example ·················································································································164
Network requirements·········································································································································164
Configuration procedure ····································································································································164
Verifying the configuration·································································································································165
Configuring DHCPv6 snooping ····························································································································· 167
Overview·······································································································································································167
Ensuring that DHCPv6 clients obtain IPv6 addresses from authorized DHCPv6 servers·····························167
Recording IP-to-MAC mappings of DHCPv6 clients·························································································168
Enabling DHCPv6 snooping ·······································································································································168
Configuring a DHCPv6 snooping trusted port ··········································································································168
Configuring the maximum number of DHCPv6 snooping entries an interface can learn ····································169
Configuring DHCPv6 snooping to support Option 18 and Option 37 ·································································169
Displaying and maintaining DHCPv6 snooping·······································································································170
DHCPv6 snooping configuration example················································································································171
Network requirements·········································································································································171
Configuration procedure ····································································································································171
Verifying the configuration·································································································································172
Configuring IPv6 DNS ············································································································································ 173
Overview·······································································································································································173
Configuring the IPv6 DNS client ································································································································173
Configuring static domain name resolution······································································································173
Configuring dynamic domain name resolution································································································173
Setting the DSCP value for IPv6 DNS packets ··········································································································174
Displaying and maintaining IPv6 DNS······················································································································174
Static domain name resolution configuration example····························································································175
Network requirements·········································································································································175
Configuration procedure ····································································································································175
Dynamic domain name resolution configuration example ······················································································176
Network requirements·········································································································································176
Configuration procedure ····································································································································176
Verifying the configuration·································································································································179
Configuring tunneling ············································································································································· 181
Overview·······································································································································································181
IPv6 over IPv4 tunneling ·····································································································································181
IPv4 over IPv4 tunneling ·····································································································································183
IPv4 over IPv6 tunneling ·····································································································································184
IPv6 over IPv6 tunneling ·····································································································································185
Protocols and standards ·····································································································································186
Tunneling configuration task list ·································································································································186
Configuring a tunnel interface····································································································································187
Configuration guidelines ····································································································································187
viii
Configuration procedure ····································································································································187
Configuring an IPv6 manual tunnel····························································································································188
Configuration prerequisites ································································································································188
Configuration guidelines ····································································································································188
Configuration procedure ····································································································································189
Configuration example ·······································································································································189
Configuring a 6to4 tunnel···········································································································································193
Configuration prerequisites ································································································································193
Configuration guidelines ····································································································································193
Configuration procedure ····································································································································193
Configuration example ·······································································································································194
Configuring an ISATAP tunnel ····································································································································196
Configuration prerequisites ································································································································196
Configuration guidelines ····································································································································197
Configuration procedure ····································································································································197
Configuration example ·······································································································································198
Configuring an IPv4 over IPv4 tunnel ························································································································200
Configuration prerequisites ································································································································200
Configuration guidelines ····································································································································200
Configuration procedure ····································································································································201
Configuration example ·······································································································································201
Configuring an IPv4 over IPv6 tunnel ························································································································205
Configuration prerequisites ································································································································205
Configuration guidelines ····································································································································205
Configuration procedure ····································································································································205
Configuration example ·······································································································································206
Configuring an IPv6 over IPv6 tunnel ························································································································209
Configuration prerequisites ································································································································209
Configuration guidelines ····································································································································209
Configuration procedure ····································································································································210
Configuration example ·······································································································································211
Displaying and maintaining tunneling configuration ·······························································································214
Troubleshooting tunneling configuration ···················································································································214
Symptom·······························································································································································214
Solution·································································································································································214
Configuring GRE····················································································································································· 216
Overview·······································································································································································216
GRE encapsulation format··································································································································216
GRE encapsulation and de-encapsulation processes ······················································································217
Protocols and standards ·····································································································································218
Configuring a GRE over IPv4 tunnel ··························································································································218
Configuration prerequisites ································································································································218
Configuration guidelines ····································································································································218
Configuration procedure ····································································································································218
Configuring a GRE over IPv6 tunnel ··························································································································219
Configuration prerequisites ································································································································219
Configuration guidelines ····································································································································219
Configuration procedure ····································································································································220
Displaying and maintaining GRE·······························································································································221
GRE over IPv4 tunnel configuration example············································································································221
GRE over IPv6 tunnel configuration example············································································································225
Troubleshooting GRE ···················································································································································228
ix
Support and other resources ·································································································································· 230
Contacting HP ······························································································································································230
Subscription service ············································································································································230
Related information······················································································································································230
Documents····························································································································································230
Websites·······························································································································································230
Conventions ··································································································································································231
Index ········································································································································································ 233
1
Configuring ARP
You can use the port link-mode command to set an Ethernet port to operate in bridge (Layer 2) or route
mode (Layer 3) (see Layer 2—LAN Switching Configuration Guide).
Overview
The Address Resolution Protocol (ARP) is used to resolve an IP address into a physical address (Ethernet
MAC address, for example).
In an Ethernet LAN, a device uses ARP to resolve the IP address of the next hop to the corresponding
MAC address.
ARP message format
ARP messages include ARP requests and ARP replies. Figure 1 shows the format of the ARP request/reply.
Numbers in the figure refer to field lengths.
Figure 1 ARP message format
ARP message fields:
•Hardware type—The hardware address type. Value 1 represents Ethernet.
•Protocol type—The type of the protocol address to be mapped. The hexadecimal value 0x0800
represents IP.
•Hardware address length and protocol address length—Length, in bytes, of a hardware address
and a protocol address. For an Ethernet address, the value of the hardware address length field is
6. For an IPv4 address, the value of the protocol address length field is 4.
•OP—Operation code, which describes type of the ARP message. Value 1 represents an ARP request,
and value 2 represents an ARP reply.
•Sender hardware address—Hardware address of the device sending the message.
•Sender protocol address—Protocol address of the device sending the message.
•Target hardware address—Hardware address of the device to which the message is being sent.
•Target protocol address—Protocol address of the device to which the message is being sent.
2
ARP operation
If Host A and Host B are on the same subnet and Host A sends a packet to Host B, as shown in Figure
2, the resolution process is:
1. Host A looks in its ARP table to see whether there is an ARP entry for Host B. If yes, Host A uses the
MAC address in the entry to encapsulate the IP packet into a data link layer frame and sends the
frame to Host B.
2. If Host A finds no entry for Host B, Host A buffers the packet and broadcasts an ARP request using
the following information:
{Source IP address and source MAC address—Host A’s own IP address and the MAC address
{Target IP address—Host B’s IP address
{Target MAC address—An all-zero MAC address
All hosts on this subnet can receive the broadcast request, but only the requested host (Host B)
processes the request.
3. Host B compares its own IP address with the target IP address in the ARP request. If they are the
same, Host B:
a. Adds the sender IP address and sender MAC address into its ARP table.
b. Encapsulates its MAC address into an ARP reply.
c. Unicasts the ARP reply to Host A.
4. After receiving the ARP reply, Host A:
a. Adds the MAC address of Host B to its ARP table.
b. Encapsulates the MAC address into the packet and sends it to Host B.
Figure 2 ARP address resolution process
If Host A and Host B are on different subnets, the resolution process is as follows:
1. Host A sends an ARP request to the gateway. The target IP address in the ARP request is the IP
address of the gateway.
2. After obtaining the MAC address of the gateway from an ARP reply, Host A sends the packet to the
gateway.
3. If the gateway maintains the ARP entry of Host B, it forwards the packet to Host B directly; if not,
it broadcasts an ARP request, in which the target IP address is the IP address of Host B.
4. After obtaining the MAC address of Host B, the gateway sends the packet to Host B.
3
ARP table
An ARP table stores dynamic and static ARP entries.
Dynamic ARP entry
ARP automatically creates and updates dynamic entries. A dynamic ARP entry is removed when its aging
timer expires or the output interface goes down, and it can be overwritten by a static ARP entry.
Static ARP entry
A static ARP entry is manually configured and maintained. It does not age out, and cannot be overwritten
by a dynamic ARP entry.
Static ARP entries protect communication between devices, because attack packets cannot modify the
IP-to-MAC mapping in a static ARP entry.
Static ARP entries can be classified into long, and short ARP entries.
•To configure a long static ARP entry, specify the IP address, MAC address, VLAN, and output
interface. A long static ARP entry is directly used for forwarding matching packets. To allow
communication with a host using a fixed IP-to-MAC mapping through a specific interface in a
specific VLAN, configure a long static ARP entry for it.
•To configure a short static ARP entry, you only need to specify the IP address and MAC address.
{If the output interface is a Layer 3 Ethernet port, the short ARP entry can be directly used for
forwarding matching packets.
{If the output interface is a VLAN interface, the device first sends an ARP request whose target
IP address is the IP address of the short entry. If the sender IP and MAC addresses in the
received ARP reply match the IP and MAC addresses of the short static ARP entry, the device
adds the interface receiving the ARP reply to the short static ARP entry, and then uses the
resolved entry to forward the matching IP packets.
To communicate with a host by using a fixed IP-to-MAC mapping, configure a short static ARP
entry for it.
Configuring a static ARP entry
A static ARP entry is effective when the device it corresponds to works properly. However, when a VLAN
or VLAN interface is deleted, any static ARP entry corresponding to it will also be deleted (if it is a long
static ARP entry) or will become unresolved (if it is a short and resolved static ARP entry).
Follow these guidelines when you configure a long static ARP entry:
•The vlan-id argument must be the ID of an existing VLAN where the ARP entry resides. The specified
Ethernet interface must belong to that VLAN. The VLAN interface of the VLAN must be created.
•The IP address of the VLAN interface of the VLAN specified by the vlan-id argument must belong to
the same subnet as the IP address specified by the ip-address argument.
To configure a static ARP entry:
Step Command Remarks
1. Enter system view. system-view N/A
4
Step Command Remarks
2. Configure a static ARP
entry.
•Configure a long static ARP entry:
arp static ip-address mac-address vlan-id
interface-type interface-number [ vpn-instance
vpn-instance-name ]
•Configure a short static ARP entry:
arp static ip-address mac-address [ vpn-instance
vpn-instance-name ]
Use either command.
Configuring the maximum number of dynamic ARP
entries for an interface
An interface can dynamically learn ARP entries. To prevent an interface from holding too many ARP
entries, you can set the maximum number of dynamic ARP entries that an interface can learn. When the
maximum number is reached, the interface stops learning ARP entries.
A Layer 2 interface can learn an ARP entry only when both its maximum number and the VLAN
interface's maximum number are not reached.
To set the maximum number of dynamic ARP entries that an interface can learn:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter Ethernet interface view. interface interface-type
interface-number N/A
3. Set the maximum number of
dynamic ARP entries that the
interface can learn.
arp max-learning-num
number
Optional.
By default, a Layer 2 interface does not
limit the number of dynamic ARP entries.
A Layer 3 interface on the HP 3600 v2
EI switch series can learn up to 8192
dynamic ARP entries. A Layer 3
interface on the HP 3600 v2 SI switch
series can learn up to 2048 dynamic
ARP entries.
If the value of the number argument is set
to 0, the interface is disabled from
learning dynamic ARP entries.
Setting the aging timer for dynamic ARP entries
Each dynamic ARP entry in the ARP table has a limited lifetime, called aging timer. The aging timer of a
dynamic ARP entry is reset each time the dynamic ARP entry is updated. Dynamic ARP entries that are not
updated before their aging timers expire are deleted from the ARP table.
To set the age timer for dynamic ARP entries:
5
Step Command Remarks
1. Enter system view. system-view N/A
2. Set the age timer for dynamic
ARP entries. arp timer aging aging-time Optional.
20 minutes by default.
Enabling dynamic ARP entry check
The dynamic ARP entry check function controls whether the device supports dynamic ARP entries with
multicast MAC addresses.
When dynamic ARP entry check is enabled, the device cannot learn dynamic ARP entries containing
multicast MAC addresses.
When dynamic ARP entry check is disabled, the device can learn dynamic ARP entries containing
multicast MAC addresses.
To enable dynamic ARP entry check:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable dynamic ARP entry
check. arp check enable Optional.
Enabled by default.
Configuring ARP quick update
HP recommends you enable ARP quick update in WLAN networks only.
As shown in Figure 3, the laptop frequently roams between AP 1 and AP 2. This affects the mapping
between its MAC address and output interface on the switch. If the switch does not update its ARP table
immediately after the output interface changes, it might fail to communicate with the laptop.
Figure 3 ARP quick update application scenario
With ARP quick update enabled, the switch updates the corresponding ARP entry immediately after the
change of the mapping between a MAC address and an output interface to ensure nonstop data
forwarding.
6
To enable ARP quick update:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable ARP quick
update.
mac-address station-move
quick-notify enable
Optional.
Disabled by default.
Configuring multicast ARP
Microsoft Network Load Balancing (NLB) is a load balancing technology for server clustering developed
on Windows Server.
NLB supports load sharing and redundancy among servers within a cluster. To implement fast failover,
NLB requires that the switch forwards network traffic to all servers or specified servers in the cluster, and
each server filters out unexpected traffic. In a medium or small data center that uses the Windows Server
operating system, the proper cooperation of the switch and NLB is very important. For more information
about NLB, see the related documents of Windows Sever.
Microsoft NLB provides the following packet sending modes to make the switch forward network traffic
to all servers or specified servers:
•Unicast mode—NLB assigns each cluster member a common MAC address, which is the cluster
MAC address, and changes the source MAC address of each sent packet. Thus, the switch cannot
add the cluster MAC address to its MAC table. In addition, because the cluster MAC address is
unknown to the switch, packets destined to it are forwarded on all the ports of the switch.
•Multicast mode—NLB uses a multicast MAC address that is a virtual MAC address for network
communication, for example 0300-5e11-1111.
•Internet Group Management Protocol (IGMP) multicast mode—The switch sends packets only out of
the ports that connect to the cluster members rather than all ports.
NOTE:
Multicast ARP is applicable to only multicast-mode NLB.
To configure multicast ARP:
Step Command Remarks
1. Disable the ARP entry check
function. undo arp check enable N/A
2. Configure a static ARP entry.
arp static ip-address mac-address
vlan-id interface-type interface-number
[ vpn-instance vpn-instance-name ]
Optional.
3. Configure a static multicast
MAC address entry.
mac-address multicast mac-address
interface interface-list vlan vlan-id
See IP Multicast Command
Reference.
7
Displaying and maintaining ARP
CAUTION:
Clearing ARP entries from the ARP table might cause communication failures.
Task Command Remarks
Display ARP entries in the ARP
table.
display arp [ [ all | dynamic | static ] [ slot
slot-number ] | vlan vlan-id | interface
interface-type interface-number ] [ count |
verbose ] [ |{ begin | exclude | include }
regular-expression ]
Available in any view
Display the ARP entry for a
specified IP address.
display arp ip-address [slot slot-number ]
[verbose ] [ | {begin |exclude |include }
regular-expression ]
Available in any view
Display the ARP entries for a
specified VPN instance.
display arp vpn-instance vpn-instance-name
[ count ] [ | {begin | exclude |include }
regular-expression ]
Available in any view
Display the age timer for dynamic
ARP entries.
display arp timer aging [ |{ begin | exclude
| include } regular-expression ] Available in any view
Clear ARP entries from the ARP
table.
reset arp { all | dynamic | static | slot
slot-number | interface interface-type
interface-number }
Available in user view
ARP configuration examples
Static ARP entry configuration example
Network requirements
As shown in Figure 4, hosts are connected to the switch, which is connected to the router through
interface Ethernet 1/0/1 in VLAN 10. The IP and MAC addresses of the router are 192.168.1.1/24 and
00e0-fc01-0000 respectively.
To prevent malicious users from attacking the switch and enhance security for communications between
the router and switch, configure a static ARP entry for the router on the switch.
8
Figure 4 Network diagram
Configuration procedure
Configure the switch:
# Create VLAN 10.
<Switch> system-view
[Switch] vlan 10
[Switch-vlan10] quit
# Add interface Ethernet 1/0/1 to VLAN 10.
[Switch] interface Ethernet 1/0/1
[Switch-Ethernet1/0/1] port link-type trunk
[Switch-Ethernet1/0/1] port trunk permit vlan 10
[Switch-Ethernet1/0/1] quit
# Create interface VLAN-interface 10 and configure its IP address.
[Switch] interface vlan-interface 10
[Switch-vlan-interface10] ip address 192.168.1.2 24
[Switch-vlan-interface10] quit
# Configure a static ARP entry that has IP address 192.168.1.1, MAC address 00e0-fc01-0000, and
output interface Ethernet 1/0/1 in VLAN 10.
[Switch] arp static 192.168.1.1 00e0-fc01-0000 10 Ethernet 1/0/1
# Display information about static ARP entries.
[Switch] display arp static
Type: S-Static D-Dynamic A-Authorized
IP Address MAC Address VLAN ID Interface Aging Type
192.168.1.1 00e0-fc01-0000 10 Eth1/0/1 N/A S
Multicast ARP configuration example
Network requirements
As shown in Figure 5, a small data center uses Microsoft multicast-mode NLB. To enable the switches to
cooperate with NLB, configure the following:
9
•Add Ethernet 1/0/2 and Ethernet 1/0/3 into VLAN 1, and specify IP address 16.1.1.30/24 for
VLAN-interface 1.
•Add Ethernet 1/0/1 and Ethernet 1/0/4 into VLAN 2, and specify IP address 17.1.1.1/24 for
VLAN-interface 2.
•S p e c i f y 17.1.1.1 / 24 a s t h e d e f a u l t g a t e wa y o f H o s t A a n d H o s t B .
•Specify 16.1.1.30/24 as the default gateway of Server A and Server B.
•Disable the ARP entry check function so that the switch can learn dynamic ARP entries containing
multicast MAC addresses.
•Configure a static multicast MAC address entry so that only interfaces Ethernet 1/0/2 and Ethernet
1/0/3 can receive multicast information.
Figure 5 Network diagram
Configuration procedure
This example only describes multicast ARP configuration on the switch, and is only applicable to multicast
NLB. For NLB configuration on the servers, see the related documents of the Windows Server.
# Specify an IP address for VLAN-interface 2.
<Switch> system-view
[Switch] vlan 2
[Switch-vlan2] port Ethernet 1/0/4
[Switch-vlan2] port Ethernet 1/0/1
[Switch-vlan2] quit
[Switch] interface vlan-interface 2
[Switch-Vlan-interface2] ip address 17.1.1.1 255.255.255.0
[Switch-Vlan-interface2] quit
# Specify an IP address for VLAN-interface 1.
[Switch] interface vlan-interface 1
[Switch-Vlan-interface1] ip address 16.1.1.30 255.255.255.0
[Switch-Vlan-interface1] quit
# Disable the ARP entry check function.
[Switch] undo arp check enable
# Configure a static multicast MAC address entry.
[Switch] mac-address multicast 03bf-1001-0164 interface Ethernet 1/0/2 Ethernet 1/0/3 vlan
1
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