H3C H3C S7500E-X User manual
H3C S7500E-X Switch Series
Layer 2 - LAN Switching
Configuration Guide
Hangzhou H3C Technologies Co., Ltd.
http://www.h3c.com
Software version: S7500EX-CMW710-R7178
Document version: 6W100-20160118
Copyright © 2016, Hangzhou H3C Technologies Co., Ltd. and its licensors
All rights reserved
No part of this manual may be reproduced or transmitted in any form or by any means without prior written
consent of Hangzhou H3C Technologies Co., Ltd.
Trademarks
H3C, , H3CS, H3CIE, H3CNE,Aolynk, , H3Care, , IRF, NetPilot, Netflow, SecEngine,
SecPath, SecCenter, SecBlade, Comware, ITCMM and HUASAN are trademarks of Hangzhou H3C
Technologies Co., Ltd.
All other trademarks that may be mentioned in this manual are the property of their respective owners
Notice
The information in this document is subject to change without notice. Every effort has been made in the
preparation of this document to ensure accuracy of the contents, but all statements, information, and
recommendations in this document do not constitute the warranty of any kind, express or implied.
Preface
This configuration guide describes LAN switching fundamentals and configuration. It describes how
to isolate uses in the same VLAN, eliminate Layer 2 loops, divide VLANs, transmit customer network
packets through the public network, and modify VLAN tags for packets.
This preface includes the following topics about the documentation:
•Audience.
•Conventions.
•About the H3C S7500E-X documentation set.
•Obtaining documentation.
•Technical support.
•Documentation feedback.
Audience
This documentation is intended for:
•Network planners.
•Field technical support and servicing engineers.
•Network administrators working with the S7500E-X switch series.
Conventions
This section describes the conventions used in the documentation.
Port numbering in examples
The port numbers in the documentation are for illustration only and might be unavailable on your
device.
Command conventions
Convention Description
Boldface Bold text represents commands and keywords that you enter literally as shown.
Italic Italic text represents arguments that you replace with actual values.
[ ] Square brackets enclose syntax choices (keywords or arguments) that are optional.
{ x | y | ... }
Braces enclose a set of required syntax choices separated by vertical bars, from which
you select one.
[ x | y | ... ]
Square brackets enclose a set of optional syntax choices separated by vertical bars,
from which you select one or none.
{ x | y | ... } *
Asterisk marked braces enclose a set of required syntax choices separated by vertical
bars, from which you select at least one.
[ x | y | ... ] *
Asterisk marked square brackets enclose optional syntax choices separated by vertical
bars, from which you select one choice, multiple choices, or none.
&<1-n> The argument or keyword and argument combination before the ampersand (&) sign
can be entered 1 to n times.
# A line that starts with a pound (#) sign is comments.
GUI conventions
Convention Description
Boldface Window names, button names, field names, and menu items are in Boldface. For
example, the New User window appears; click OK.
> Multi-level menus are separated by angle brackets. For example, File > Create >
Folder.
Symbols
Convention Description
WARNING! An alert that calls attention to important information that if not understood or followed
can result in personal injury.
CAUTION: An alert that calls attention to important information that if not understood or followed
can result in data loss, data corruption, or damage to hardware or software.
IMPORTANT: An alert that calls attention to essential information.
NOTE: An alert that contains additional or supplementary information.
TIP: An alert that provides helpful information.
Network topology icons
Convention Description
Represents a generic network device, such as a router, switch, or firewall.
Represents a routing-capable device, such as a router or Layer 3 switch.
Represents a generic switch, such as a Layer 2 or Layer 3 switch, or a router that
supports Layer 2 forwarding and other Layer 2 features.
Represents an access controller, a unified wired-WLAN module, or the access
controller engine on a unified wired-WLAN switch.
Represents an access point.
Wireless terminator unit.
Wireless terminator.
Represents a mesh access point.
Represents omnidirectional signals.
Represents directional signals.
Represents a security product, such as a firewall, UTM, multiservice security
gateway, or load balancing device.
T
T
T
T
Convention Description
Represents a security card, such as a firewall, load balancing, NetStream, SSL VPN,
IPS, or ACG card.
About the H3C S7500E-X documentation set
The H3C S7500E-X documentation set includes the following categories of documents:
Category Documents Purposes
Hardware specifications
and installation
Quick start Guides you through initial installation and setup
procedures to help you quickly set up and use
your device with the minimum configuration.
Installation guide Provides a complete guide to hardware
installation and hardware specifications.
H3C Pluggable SFP
[SFP+][XFP] Transceiver
Modules Installation Guide
Guides you through installing SFP/SFP+/XFP
transceiver modules.
H3C CFP Transceiver
Modules Installation Guide Guides you through installing CFP transceiver
modules.
H3C QSFP+ Transceiver
Modules Installation Guide Guides you through installing QSFP+
transceiver modules.
H3C Transceiver Modules
User Guide
Describes the transceiver modules available
for the H3C network products, their external
views, and specifications.
Software configuration
Configuration guides Describes software features and configuration
procedures.
Command references Provides a quick reference to all available
commands.
Configuration examples Describes typical network scenarios and
provide configuration examples and
instructions.
Operations and
maintenance
Troubleshooting Provides troubleshooting information for
common problems of using the product.
FAQ Covers the most frequently asked questions
about the hardware, software and system
specifications.
Release notes
Provides information about the product
release, including the version history, hardware
and software compatibility matrix, version
upgrade information, technical support
information, and software upgrading.
System log messages Explains the system log messages.
Obtaining documentation
Access the most up-to-date H3C product documentation on the World Wide Web
at http://www.h3c.com.
Click the following links to obtain different categories of product documentation:
[Technical Documents]—Provides hardware installation, software upgrading, and software feature
configuration and maintenance documentation.
[Products & Solutions]—Provides information about products and technologies, as well as
solutions. [Software Download]—Provides the documentation released with the software version.
Technical support
service@h3c.com
http://www.h3c.com
Documentation feedback
You can e-mail your comments about product documentation to info@h3c.com.
We appreciate your comments.
i
Contents
Configuring the MAC address table ································································ 1
Overview ····························································································································································1
How a MAC address entry is created·········································································································1
Types of MAC address entries···················································································································1
MAC address table configuration task list ··········································································································2
Configuring MAC address entries ······················································································································3
Configuration guidelines·····························································································································3
Adding or modifying a static or dynamic MAC address entry globally ·······················································3
Adding or modifying a static or dynamic MAC address entry on an interface············································3
Adding or modifying a blackhole MAC address entry ················································································4
Adding or modifying a multiport unicast MAC address entry ·····································································4
Disabling MAC address learning························································································································5
Disabling global MAC address learning ·····································································································5
Disabling MAC address learning on interfaces ··························································································6
Disabling MAC address learning on a VLAN ·····························································································6
Setting the aging timer for dynamic MAC address entries ·················································································6
Setting the MAC learning limit on an interface ···································································································7
Configuring the unknown frame forwarding rule after the MAC learning limit on an interface is reached ·········7
Assigning MAC learning priority to interfaces ····································································································8
Enabling MAC address synchronization ············································································································9
Configuring MAC address move notifications and suppression·······································································11
Configuring MAC address move notifications ··························································································11
Configuring MAC address move suppression··························································································11
Enabling ARP fast update for MAC address moves ························································································12
Disabling static source check···························································································································13
Enabling SNMP notifications for the MAC address table·················································································13
Displaying and maintaining the MAC address table ························································································14
MAC address table configuration example ······································································································14
Network requirements ······························································································································14
Configuration procedure···························································································································15
Verifying the configuration························································································································15
Configuring MAC Information········································································ 16
Enabling MAC Information ·······························································································································16
Setting the MAC Information mode··················································································································16
Setting the MAC change notification interval ···································································································17
Setting the MAC Information queue length ······································································································17
MAC Information configuration example··········································································································17
Network requirements ······························································································································17
Configuration restrictions and guidelines ·································································································18
Configuration procedure···························································································································18
Configuring Ethernet link aggregation··························································· 20
Basic concepts·················································································································································20
Aggregation group, member port, and aggregate interface ·····································································20
Aggregation states of member ports in an aggregation group ·································································20
Operational key ········································································································································21
Configuration types ··································································································································21
Link aggregation modes···························································································································22
Aggregating links in static mode ······················································································································22
Choosing a reference port························································································································22
Setting the aggregation state of each member port ·················································································22
Aggregating links in dynamic mode ·················································································································23
LACP························································································································································23
How dynamic link aggregation works·······································································································25
Edge aggregate interface·································································································································27
Load sharing modes for link aggregation groups·····························································································27
ii
Ethernet link aggregation configuration task list ······························································································27
Configuring an aggregation group ···················································································································28
Configuration restrictions and guidelines ·································································································28
Configuring a static aggregation group ····································································································29
Configuring a dynamic aggregation group ·······························································································30
Configuring an aggregate interface··················································································································32
Setting the description for an aggregate interface ···················································································32
Specifying ignored VLANs for a Layer 2 aggregate interface ··································································33
Reserving a VLAN interface resource for a Layer 2 aggregate interface·················································33
Setting the MTU for a Layer 3 aggregate interface ··················································································34
Setting the minimum and maximum numbers of Selected ports for an aggregation group ·····················34
Setting the expected bandwidth for an aggregate interface·····································································35
Configuring an edge aggregate interface·································································································35
Shutting down an aggregate interface ·····································································································36
Restoring the default settings for an aggregate interface ········································································36
Configuring load sharing for link aggregation groups ······················································································37
Setting load sharing modes for link aggregation groups ··········································································37
Enabling local-first load sharing for link aggregation················································································38
Enabling link-aggregation traffic redirection·····································································································39
Configuration restrictions and guidelines ·································································································39
Configuration procedure···························································································································40
Displaying and maintaining Ethernet link aggregation ·····················································································40
Ethernet link aggregation configuration examples ···························································································40
Layer 2 static aggregation configuration example····················································································40
Layer 2 dynamic aggregation configuration example···············································································42
Layer 2 aggregation load sharing configuration example ········································································44
Layer 2 edge aggregate interface configuration example ········································································46
Layer 3 static aggregation configuration example····················································································48
Layer 3 dynamic aggregation configuration example···············································································49
Layer 3 aggregation load sharing configuration example ········································································50
Layer 3 edge aggregate interface configuration example ········································································52
Configuring port isolation ·············································································· 54
Assigning a port to an isolation group··············································································································54
Displaying and maintaining port isolation·········································································································55
Port isolation configuration example ················································································································55
Network requirements ······························································································································55
Configuration procedure···························································································································55
Verifying the configuration························································································································56
Configuring spanning tree protocols ····························································· 58
STP ··································································································································································58
STP protocol packets ·······························································································································58
Basic concepts in STP ·····························································································································58
Calculation process of the STP algorithm ································································································59
RSTP ·······························································································································································65
PVST································································································································································65
MSTP ·······························································································································································66
MSTP features ·········································································································································66
MSTP basic concepts ······························································································································66
How MSTP works·····································································································································70
MSTP implementation on devices············································································································70
Protocols and standards ··································································································································71
General configuration restrictions and guidelines ····························································································71
Spanning tree configuration task lists ··············································································································72
STP configuration task list························································································································72
RSTP configuration task list ·····················································································································72
PVST configuration task list ·····················································································································73
MSTP configuration task list·····················································································································74
Setting the spanning tree mode ·······················································································································75
Configuring an MST region ······························································································································75
Configuring the root bridge or a secondary root bridge ···················································································76
iii
Configuring the current device as the root bridge of a specific spanning tree ·········································76
Configuring the current device as a secondary root bridge of a specific spanning tree···························77
Configuring the device priority ·························································································································77
Configuring the maximum hops of an MST region···························································································77
Configuring the network diameter of a switched network ················································································78
Setting spanning tree timers ····························································································································78
Configuration restrictions and guidelines ·································································································79
Configuration procedure···························································································································79
Setting the timeout factor ·································································································································80
Setting the BPDU transmission rate ················································································································80
Configuring edge ports·····································································································································81
Configuration restrictions and guidelines ·································································································81
Configuration procedure···························································································································81
Configuring path costs of ports ························································································································81
Specifying a standard for the device to use when it calculates the default path cost ······························81
Configuring path costs of ports ················································································································84
Configuration example ·····························································································································84
Configuring the port priority······························································································································85
Configuring the port link type ···························································································································85
Configuration restrictions and guidelines ·································································································85
Configuration procedure···························································································································86
Configuring the mode a port uses to recognize and send MSTP packets ·······················································86
Enabling outputting port state transition information························································································86
Enabling the spanning tree feature ··················································································································87
Enabling the spanning tree feature in STP/RSTP/MSTP mode·······························································87
Enabling the spanning tree feature in PVST mode ··················································································87
Performing mCheck ·········································································································································88
Performing mCheck globally ····················································································································88
Performing mCheck in interface view·······································································································88
Configuring Digest Snooping ···························································································································88
Configuration restrictions and guidelines ·································································································89
Configuration procedure···························································································································89
Digest Snooping configuration example···································································································90
Configuring No Agreement Check ···················································································································90
Configuration prerequisites ······················································································································92
Configuration procedure···························································································································92
No Agreement Check configuration example···························································································92
Configuring TC Snooping·································································································································92
Configuration restrictions and guidelines ·································································································93
Configuration procedure···························································································································93
Configuring protection features························································································································94
Configuring BPDU guard··························································································································94
Enabling root guard··································································································································95
Enabling loop guard ·································································································································95
Configuring port role restriction ················································································································96
Configuring TC-BPDU transmission restriction ························································································96
Enabling TC-BPDU guard ························································································································97
Enabling BPDU drop ································································································································97
Enabling SNMP notifications for new-root election and topology change events ············································98
Displaying and maintaining the spanning tree ·································································································98
Spanning tree configuration example ··············································································································99
MSTP configuration example ···················································································································99
PVST configuration example··················································································································103
Configuring loop detection ·········································································· 107
Overview ························································································································································107
Loop detection mechanism ····················································································································107
Loop detection interval ···························································································································108
Loop protection actions ··························································································································108
Port status auto recovery ·······················································································································108
Loop detection configuration task list·············································································································109
Enabling loop detection··································································································································109
iv
Enabling loop detection globally·············································································································109
Enabling loop detection on a port···········································································································109
Setting the loop protection action···················································································································109
Setting the global loop protection action ································································································110
Setting the loop protection action on a Layer 2 Ethernet interface ························································110
Setting the loop protection action on a Layer 2 aggregate interface······················································110
Setting the loop detection interval··················································································································110
Displaying and maintaining loop detection·····································································································111
Loop detection configuration example ···········································································································111
Network requirements ····························································································································111
Configuration procedure·························································································································111
Verifying the configuration······················································································································112
Configuring VLANs ····················································································· 114
Overview ························································································································································114
VLAN frame encapsulation ····················································································································114
Protocols and standards ························································································································115
Configuring basic VLAN settings ···················································································································115
Configuring basic settings of a VLAN interface······························································································116
Configuring port-based VLANs ······················································································································117
Introduction ············································································································································117
Assigning an access port to a VLAN······································································································118
Assigning a trunk port to a VLAN ···········································································································119
Assigning a hybrid port to a VLAN ·········································································································120
Configuring MAC-based VLANs ····················································································································121
Introduction ············································································································································121
General configuration restrictions and guidelines ··················································································123
Configuring static MAC-based VLAN assignment··················································································123
Configuring dynamic MAC-based VLAN assignment·············································································124
Configuring server-assigned MAC-based VLAN····················································································125
Configuring IP subnet-based VLANs ·············································································································125
Configuring protocol-based VLANs················································································································126
Configuring a VLAN group ·····························································································································127
Displaying and maintaining VLANs ················································································································128
VLAN configuration examples························································································································128
Port-based VLAN configuration example ·······························································································128
MAC-based VLAN configuration example······························································································130
IP subnet-based VLAN configuration example ······················································································132
Protocol-based VLAN configuration example ························································································133
Configuring super VLANs ··········································································· 137
Super VLAN configuration task list ················································································································137
Creating a sub-VLAN ·····································································································································137
Configuring a super VLAN ·····························································································································137
Configuring a super VLAN interface ··············································································································138
Displaying and maintaining super VLANs ······································································································138
Super VLAN configuration example ···············································································································139
Network requirements ····························································································································139
Configuration procedure·························································································································139
Verifying the configuration······················································································································140
Configuring the private VLAN ····································································· 142
Configuration task list·····································································································································142
Configuration restrictions and guidelines ·······································································································143
Configuration procedure ································································································································143
Displaying and maintaining the private VLAN································································································145
Private VLAN configuration examples ···········································································································146
Promiscuous port configuration example ·······························································································146
Trunk promiscuous port configuration example ·····················································································148
Trunk promiscuous and trunk secondary port configuration example····················································152
Secondary VLAN Layer 3 communication configuration example ·························································155
v
Configuring voice VLANs ············································································ 158
Overview ························································································································································158
Methods of identifying IP phones···················································································································158
Identifying IP phones through OUI addresses ·······················································································158
Automatically identifying IP phones through LLDP ················································································159
Advertising the voice VLAN information to IP phones ···················································································159
IP phone access methods······························································································································159
Connecting the host and the IP phone in series ····················································································159
Connecting the IP phone to the device ··································································································160
Voice VLAN assignment modes ····················································································································160
Automatic mode ·····································································································································160
Manual mode ·········································································································································161
Cooperation of voice VLAN assignment modes and IP phones ····························································161
Security mode and normal mode of voice VLANs ·························································································162
Voice VLAN configuration task list ·················································································································163
Configuring the QoS priority settings for voice traffic ·····················································································163
Configuring a port to operate in automatic voice VLAN assignment mode····················································164
Configuration restrictions and guidelines ·······························································································164
Configuration procedure·························································································································164
Configuring a port to operate in manual voice VLAN assignment mode ·······················································165
Configuration restrictions and guidelines ·······························································································165
Configuration procedure·························································································································165
Enabling LLDP for automatic IP phone discovery··························································································166
Configuration restrictions and guidelines ·······························································································166
Configuration procedure·························································································································166
Configuring LLDP to advertise a voice VLAN ································································································166
Configuring CDP to advertise a voice VLAN··································································································167
Displaying and maintaining voice VLANs ······································································································168
Voice VLAN configuration examples··············································································································168
Automatic voice VLAN assignment mode configuration example··························································168
Manual voice VLAN assignment mode configuration example ······························································170
Configuring MVRP ······················································································ 172
MRP ·······························································································································································172
MRP implementation······························································································································172
MRP messages······································································································································172
MRP timers ············································································································································174
MVRP registration modes ······························································································································175
Protocols and standards ································································································································175
MVRP configuration task list ··························································································································175
Configuration restrictions and guidelines ·······································································································175
Configuration prerequisites ····························································································································176
Enabling MVRP··············································································································································176
Configuring an MVRP registration mode ·······································································································176
Configuring MRP timers·································································································································177
Enabling GVRP compatibility ·························································································································178
Displaying and maintaining MVRP·················································································································178
MVRP configuration example ························································································································178
Network requirements ····························································································································178
Configuration procedure·························································································································179
Verifying the configuration······················································································································182
Configuring QinQ ························································································ 189
Overview ························································································································································189
How QinQ works ····································································································································189
QinQ implementations····························································································································190
Protocols and standards ························································································································190
Restrictions and guidelines ····························································································································191
Enabling QinQ················································································································································191
Configuring transparent transmission for VLANs···························································································191
Configuring the TPID for VLAN tags ··············································································································192
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Configuring the CVLAN TPID·················································································································192
Configuring the SVLAN TPID·················································································································193
Setting the 802.1p priority in SVLAN tags······································································································193
Displaying and maintaining QinQ···················································································································194
QinQ configuration examples·························································································································195
Basic QinQ configuration example·········································································································195
VLAN transparent transmission configuration example ·········································································197
Configuring VLAN mapping ········································································ 199
Overview ························································································································································199
Application scenario of one-to-one and many-to-one VLAN mapping ···················································199
Application scenario of one-to-two and two-to-two VLAN mapping ·······················································201
VLAN mapping implementations············································································································201
VLAN mapping configuration task list ············································································································204
Configuring one-to-one VLAN mapping ·········································································································204
Configuring many-to-one VLAN mapping ······································································································205
Configuration restrictions and guidelines ·······························································································205
Many-to-one VLAN mapping configuration task list ···············································································205
Enabling DHCP snooping ······················································································································206
Enabling ARP detection ·························································································································206
Configuring the customer-side port ········································································································206
Configuring the network-side port ··········································································································207
Configuring one-to-two VLAN mapping ·········································································································207
Configuring two-to-two VLAN mapping··········································································································208
Displaying and maintaining VLAN mappings ·································································································209
VLAN mapping configuration examples·········································································································209
One-to-one and many-to-one VLAN mapping configuration example ···················································209
One-to-two and two-to-two VLAN mapping configuration example ·······················································214
Configuring LLDP························································································ 217
Overview ························································································································································217
Basic concepts ·······································································································································217
Working mechanism·······························································································································222
Protocols and standards ························································································································223
LLDP configuration task list ···························································································································223
Performing basic LLDP configurations···········································································································224
Enabling LLDP ·······································································································································224
Setting the LLDP bridge mode ···············································································································224
Setting the LLDP operating mode ··········································································································224
Setting the LLDP reinitialization delay····································································································225
Enabling LLDP polling····························································································································225
Configuring the advertisable TLVs ·········································································································226
Configuring the management address and its encoding format·····························································228
Setting other LLDP parameters··············································································································229
Setting an encapsulation format for LLDP frames ·················································································230
Disabling LLDP PVID inconsistency check ····························································································230
Configuring CDP compatibility ·······················································································································231
Configuration prerequisites ····················································································································231
Configuration procedure·························································································································231
Configuring DCBX··········································································································································232
DCBX configuration task list···················································································································233
Enabling LLDP and DCBX TLV advertising ···························································································233
Setting the DCBX version ······················································································································234
Configuring APP parameters ·················································································································234
Configuring ETS parameters··················································································································236
Configuring PFC parameters ·················································································································238
Configuring LLDP trapping and LLDP-MED trapping ····················································································238
Displaying and maintaining LLDP ··················································································································239
LLDP configuration examples ························································································································239
Basic LLDP configuration example ········································································································239
CDP-compatible LLDP configuration example·······················································································244
DCBX configuration example ·················································································································245
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Configuring service loopback groups·························································· 251
Overview ························································································································································251
Configuration restrictions and guidelines ·······································································································251
Configuring a service loopback group············································································································252
Displaying and maintaining service loopback groups ····················································································252
Service loopback group configuration example ·····························································································252
Network requirements ····························································································································252
Configuration procedure·························································································································252
Index ··········································································································· 254
1
Configuring the MAC address table
Overview
An Ethernet device uses a MAC address table to forward frames. A MAC address entry includes a
destination MAC address, an outgoing interface, and a VLAN ID. When the device receives a frame,
it uses the destination MAC address of the frame to look for a match in the MAC address table.
•The device forwards the frame out of the outgoing interface in the matching entry if a match is
found.
•The device floods the frame in the VLAN of the frame if no match is found.
How a MAC address entry is created
The entries in the MAC address table include entries automatically learned by the device and entries
manually added.
MAC address learning
The device can automatically populate its MAC address table by learning the source MAC addresses
of incoming frames on each interface.
When a frame arrives at an interface (for example, port A), the device performs the following tasks:
1. Checks the source MAC address (for example, MAC-SOURCE) of the frame.
2. Looks up the source MAC address in the MAC address table.
{The device updates the entry if an entry is found.
{The device adds an entry for MAC-SOURCE and port A if no entry is found.
3. When the device receives a frame destined for MAC-SOURCE after learning this source MAC
address, the device performs the following tasks:
a. Finds the MAC-SOURCE entry in the MAC address table.
b. Forwards the frame out of port A.
The device performs the learning process each time it receives a frame with an unknown source
MAC address until the table is fully populated.
Manually configuring MAC address entries
Dynamic MAC address learning does not distinguish between illegitimate and legitimate frames,
which can invite security hazards. When Host A is connected to port A, a MAC address entry will be
learned for the MAC address of Host A (for example, MAC A). When an illegal user sends frames
with MAC A as the source MAC address to port B, the device performs the following tasks:
1. Learns a new MAC address entry with port B as the outgoing interface and overwrites the old
entry for MAC A.
2. Forwards frames destined for MAC A out of port B to the illegal user.
As a result, the illegal user obtains the data of Host A. To improve the security for Host A, manually
configure a static entry to bind Host A to port A. Then, the frames destined for Host A are always sent
out of port A. Other hosts using the forged MAC address of Host A cannot obtain the frames destined
for Host A.
Types of MAC address entries
A MAC address table can contain the following types of entries:
2
•Static entries—A static entry is manually added to forward frames with a specific destination
MAC address out of the associated interface, and it never ages out. A static entry has higher
priority than a dynamically learned one.
•Dynamic entries—A dynamic entry can be manually configured or dynamically learned to
forward frames with a specific destination MAC address out of the associated interface. A
dynamic entry might age out. A manually configured dynamic entry has the same priority as a
dynamically learned one.
•Blackhole entries—A blackhole entry is manually configured and never ages out. A blackhole
entry is configured for filtering out frames with a specific source or destination MAC address.
For example, to block all frames destined for or sourced from a user, you can configure the
MAC address of the user as a blackhole MAC address entry. A blackhole entry has higher
priority than a dynamically learned one.
•Multiport unicast entries—A multiport unicast entry is manually added to send frames with a
specific unicast destination MAC address out of multiple ports, and it never ages out. A multiport
unicast entry has higher priority than a dynamically learned one.
A static, blackhole, or multiport unicast MAC address entry can overwrite a dynamic MAC address
entry, but not vice versa. A static entry, a blackhole entry, and a multiport unicast entry cannot
overwrite one another.
MAC address table configuration task list
The configuration tasks discussed in the following sections can be performed in any order.
This document covers only the configuration of unicast MAC address entries, including static,
dynamic, blackhole, and multiport unicast MAC address entries. For information about configuring
static multicast MAC address entries, see IP Multicast Configuration Guide. For information about
MAC address table configuration in VPLS, see MPLS Configuration Guide.
To configure the MAC address table, perform the following tasks:
Tasks at a glance
(Optional.) Configuring MAC address entries
•Adding or modifying a static or dynamic MAC address entry globally
•Adding or modifying a static or dynamic MAC address entry on an interface
•Adding or modifying a blackhole MAC address entry
•Adding or modifying a multiport unicast MAC address entry
(Optional.) Disabling MAC address learning
(Optional.) Setting the aging timer for dynamic MAC address entries
(Optional.) Setting the MAC learning limit on an interface
(Optional.) Configuring the unknown frame forwarding rule after the MAC learning limit on an interface is
reached
(Optional.) Assigning MAC learning priority to interfaces
(Optional.) Enabling MAC address synchronization
(Optional.) Configuring MAC address move notifications and suppression
(Optional.) Enabling ARP fast update for MAC address moves
(Optional.) Disabling static source check
(Optional.) Enabling SNMP notifications for the MAC address table
3
Configuring MAC address entries
Configuration guidelines
•You cannot add a dynamic MAC address entry if a learned entry already exists with a different
outgoing interface for the MAC address.
•The manually configured static, blackhole, and multiport unicast MAC address entries cannot
survive a reboot if you do not save the configuration. The manually configured dynamic MAC
address entries are lost upon reboot whether or not you save the configuration.
A frame whose source MAC address matches different types of MAC address entries is processed
differently.
Type Description
Static MAC address entry Forwards the frame according to the destination MAC address regardless of
whether the frame's ingress interface is the same as that in the entry.
Multiport unicast MAC
address entry
•Learns the MAC address (MAC A) of the frame and generates a dynamic
MAC address entry, but the entry does not take effect.
•Forwards frames destined for MAC A based on the multiport unicast
MAC address entry.
Dynamic MAC address
entry
•Learns the MAC address of the frames received on a different interface
from that in the entry and overwrites the original entry.
•Forwards the frame received on the same interface as that in the entry
and updates the aging timer for the entry.
Blackhole MAC address
entry Discards the frame.
Adding or modifying a static or dynamic MAC address entry
globally
Step Command Remarks
1. Enter system
view. system-view N/A
2. Add or modify a
static or dynamic
MAC address
entry.
mac-address { dynamic |static }mac-address
interface interface-type interface-number vlan
vlan-id
By default, no MAC address
entry is configured globally.
Make sure you have created
the VLAN and assigned the
interface to the VLAN.
Adding or modifying a static or dynamic MAC address entry
on an interface
Step Command Remarks
1. Enter system view. system-view N/A
4
Step Command Remarks
2. Enter interface view.
•Enter Layer 2 Ethernet
interface view:
interface interface-type
interface-number
•Enter Layer 2 aggregate
interface view:
interface
bridge-aggregation
interface-number
•Enter S-channel interface
view:
interface s-channel
interface-number.channel-id
•Enter S-channel aggregate
interface view:
interface
schannel-aggregation
interface-number:channel-id
N/A
3. Add or modify a static or
dynamic MAC address entry. mac-address { dynamic |
static }mac-address vlan vlan-id
By default, no MAC address entry
is configured on the interface.
Make sure you have created the
VLAN and assigned the interface
to the VLAN.
Adding or modifying a blackhole MAC address entry
Step Command Remarks
1. Enter system view. system-view N/A
2. Add or modify a blackhole
MAC address entry. mac-address blackhole
mac-address vlan vlan-id
By default, no blackhole MAC
address entry is configured.
Make sure you have created the
VLAN.
Adding or modifying a multiport unicast MAC address entry
You can configure a multiport unicast MAC address entry to associate a unicast destination MAC
address with multiple ports. The frame with a destination MAC address matching the entry is sent out
of multiple ports.
For example, when a group of servers are processing a request from a client, the client does not
need to know that more than one server is responding. In this case, you can configure a multiport
unicast MAC address entry on the device connected to the server group. Then, the device forwards
the frame destined for the server group to every server in the group.
You can configure a multiport unicast MAC address entry globally or on an interface.
Configuring a multiport unicast MAC address entry globally
Step Command Remarks
1. Enter system view. system-view N/A
5
Step Command Remarks
2. Add or modify a multiport
unicast MAC address entry.
mac-address multiport
mac-address interface
interface-list vlan vlan-id
By default, no multiport unicast
MAC address entry is configured
globally.
Make sure you have created the
VLAN and assigned the interface
to the VLAN.
Configuring a multiport unicast MAC address entry on an interface
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view.
•Enter Layer 2 Ethernet
interface view:
interface interface-type
interface-number
•Enter Layer 2 aggregate
interface view:
interface
bridge-aggregation
interface-number
N/A
3. Add the interface to a
multiport unicast MAC
address entry.
mac-address multiport
mac-address vlan vlan-id
By default, no multiport unicast
MAC address entry is configured
on the interface.
Make sure you have created the
VLAN and assigned the interface
to the VLAN.
Disabling MAC address learning
MAC address learning is enabled by default. To prevent the MAC address table from being saturated
when the device is experiencing attacks, disable MAC address learning. For example, you can
disable MAC address learning to prevent the device from being attacked by a large amount of frames
with different source MAC addresses.
After MAC address learning is disabled, existing dynamic MAC address entries age out when the
aging timer expires.
Disabling global MAC address learning
After you disable global MAC address learning, the device stops learning MAC addresses on all
interfaces.
The global MAC address learning configuration does not take effect on a VPLS VSI or an S-channel.
For information about VSIs, see MPLS Configuration Guide. For information about S-channels, see
EVB Configuration Guide.
To disable global MAC address learning:
Step Command Remarks
1. Enter system view. system-view N/A
2. Disable global MAC address
learning. undo mac-address
mac-learning enable By default, global MAC address
learning is enabled.
6
Disabling MAC address learning on interfaces
When global MAC address learning is enabled, you can disable MAC address learning on a single
interface.
To disable MAC address learning on an interface:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view.
•Enter Layer 2 Ethernet interface
view:
interface interface-type
interface-number
•Enter Layer 2 aggregate
interface view:
interface bridge-aggregation
interface-number
•Enter S-channel interface view:
interface s-channel
interface-number.channel-id
•Enter S-channel aggregate
interface view:
interface
schannel-aggregation
interface-number:channel-id
N/A
3. Disable MAC address
learning on the interface. undo mac-address mac-learning
enable
By default, MAC address
learning on the interface is
enabled.
Disabling MAC address learning on a VLAN
When global MAC address learning is enabled, you can disable MAC address learning on a
per-VLAN basis.
To disable MAC address learning on a VLAN:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable global MAC address
learning. mac-address mac-learning
enable By default, global MAC address
learning is enabled.
3. Enter VLAN view. vlan vlan-id N/A
4. Disable MAC address
learning on the VLAN. undo mac-address
mac-learning enable By default, MAC address learning
on the VLAN is enabled.
Setting the aging timer for dynamic MAC address
entries
For security and efficient use of table space, the MAC address table uses an aging timer for each
dynamic MAC address entry. If a dynamic MAC address entry is not updated before the aging timer
7
expires, the device deletes the entry. This aging mechanism ensures that the MAC address table can
promptly update to accommodate latest network topology changes.
A stable network requires a longer aging interval, and an unstable network requires a shorter aging
interval.
An aging interval that is too long might cause the MAC address table to retain outdated entries. As a
result, the MAC address table resources might be exhausted, and the MAC address table might fail
to update its entries to accommodate the latest network changes.
An interval that is too short might result in removal of valid entries, which would cause unnecessary
floods and possibly affect the device performance.
To reduce floods on a stable network, set a long aging timer or disable the timer to prevent dynamic
entries from unnecessarily aging out. Reducing floods improves the network performance. Reducing
flooding also improves the security because it reduces the chances for a data frame to reach
unintended destinations.
To set the aging timer for dynamic MAC address entries:
Step Command Remarks
1. Enter system view. system-view N/A
2. Set the aging timer for
dynamic MAC address
entries.
mac-address timer { aging
seconds | no-aging }
The default setting is 300
seconds.
The no-aging keyword disables
the aging timer.
Setting the MAC learning limit on an interface
This feature limits the MAC address table size. A large MAC address table will degrade forwarding
performance.
The MAC learning limit does not take effect on TRILL ports.
To set the MAC learning limit on an interface:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter Layer 2 Ethernet
interface view. interface interface-type
interface-number N/A
3. Set the MAC learning limit on
the interface. mac-address max-mac-count
count
By default, the number of learned
MAC addresses is not limited.
Configuring the unknown frame forwarding rule
after the MAC learning limit on an interface is
reached
You can enable or disable forwarding of unknown frames after the MAC learning limit is reached.
In this document, unknown frames refer to frames whose source MAC addresses are not in the MAC
address table.
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