Cisco Catalyst Series Switch 2940 Manual

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© 2003 Cisco Systems, Inc. All rights reserved.
Session Number
Presentation_ID
Cisco Catalyst 2940 Series Switches
Smartports Macros
March 8, 2004

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Smartports Global Configuration
Cisco Catalyst 2940 Series
! VTP Transparent mode is current Best Practice
vtp domain [smartports]
vtp mode transparent
! Enable aggressive mode UDLD on all fiber uplinks
udld aggressive
! Enable Rapid PVST+ and Loopguard
spanning-tree mode rapid-pvst
spanning-tree loopguard default
spanning-tree extend system-id

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Technical Whys
Global Configuration
•udld aggressive
Software backup to GBIC hardware features
Helps prevent spanning tree issues
•spanning-tree mode rapid-pvst
Enable 802.1w per VLAN Spanning Tree
Allows quicker convergence times
•spanning-tree loopguard default
Helps prevent errant spanning tree loops
•spanning-tree extend system-id
Allows for VLAN IDs greater than 1024

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Smartports Cisco IOS Standard Desktop
Cisco Catalyst 2940 Series
! Reset all end-station interfaces to default configuration (global command)
default interface range FastEthernet0/[1 – 8]
! Basic interface - Enable data VLAN only
interface range FastEthernet0/[1 – 8]
switchport access vlan $AVID
switchport mode access
! Enable port security limiting port to a single MAC addresses.
! Ensure age is greater than one minute and use inactivity timer
switchport port-security
! “Port-security maximum 1” is the default and will not
! Show up in the config
switchport port-security violation restrict
switchport port-security aging time 2
switchport port-security aging type inactivity
! Configure port as an edge network port
spanning-tree portfast
spanning-tree bpduguard enable
! Remark all inbound data packets with COS=0
mls qos cos override

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Technical Whys
Desktop Configuration
•switchport port-security
Turn on port level MAC address security
•switchport port-security maximum 1 (or 3 for phones)
If port security is turned on, the default number of allowed MAC addresses is 1. For an IP phone, we need 3 – one for
the workstation, one for the phone on the voice VLAN and one for the phone on the native VLAN for Cisco® Discovery
Protocol.
•switchport port-security aging type inactivity
“Unlearn” MAC addresses once they have not been used for a while. The type of “inactivity” is needed for Cisco
Discovery Protocol from IP phones to be stable. During the MAC relearn process, packets can become out-of-order or
dropped. Using type “inactivity” helps prevent this after a MAC address is learned – especially for voice traffic.
•switchport port-security aging time 2
Two minutes is the shortest time possible and not have keep-alive problems with Cisco Discovery Protocol.
Also, IP phones do not signal the switch when a workstation is unplugged. Without specifying an aging time, the MAC
address would never age out.
•switchport port-security violation restrict
Do not take the port down when a violation occurs. Instead, allow the MAC addresses that we have already seen to
continue working. All other traffic is dropped. Necessary with IP phones.
•default interface
Used to return the interface to a known configuration state

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Technical Whys
Desktop Configuration (continued)
•spanning-tree portfast
This allows the port to pass traffic soon after the port
becomes active – without waiting for spanning tree (~3 sec)
•spanning-tree bpduguard enable
Disable the port if a switch or bridge is attached to this
port. Inhibits errant network topologies and rogue
switches.

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Smartports Cisco IOS Standard Desktop with IP Phone
Cisco Catalyst 2940 Series
! Reset all end-station interfaces to default configuration (global command)
default interface range FastEthernet0/[1 – 8]
! VoIP enabled interface - Enable voice (VVID) and data VLAN
interface range FastEthernet0/[1 - 48]
switchport access vlan $AVID
switchport mode access
switchport voice vlan $VVID
! Enable port security limiting port to 3 MAC addresses. Ensure age is
! greater than one minute and use inactivity timer
switchport port-security
switchport port-security maximum 3
switchport port-security violation restrict
switchport port-security aging time 2
switchport port-security aging type inactivity
! Enable qos to extend trust to attached Cisco phone
mls qos trust device cisco-phone
! Configure port as an edge network port
spanning-tree portfast
spanning-tree bpduguard enable

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Smartports Cisco IOS Switch Uplink
Cisco Catalyst 2940 Series
! Reset all uplink interfaces to default configuration (global command)
default interface GigabitEthernet0/1
! Uplink to Distribution
default interface GigabitEthernet0/1
! Define unique Native VLAN on trunk ports
switchport trunk encapsulation dot1q
switchport trunk native vlan $NVID
#switchport trunk allowed vlan (VRANGE) #commented out to show capability
! Hardcode trunk and disable negotiation to speed up convergence
switchport mode trunk
switchport nonegotiate
! Configure qos to trust this interface
mls qos trust cos
! 802.1w defines the link as pt-pt for rapid convergence
spanning-tree link-type point-to-point

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Technical Whys
Cisco IOS Switch Uplink
•switchport nonegotiate
This command speeds up convergence times but if issued
before both sides of the trunk have been configured for
802.1q can cause the port to shut down. The default trunk
type is ISL on many switches. When the trunk is up and
configured for 802.1q, the “switchport nonegotiate” can
safely be entered
•switchport trunk allowed VLAN [data,voice,native]
This provides absolute control over which VLANs this
switch will accept.

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© 2003 Cisco Systems, Inc. All rights reserved.
Presentation_ID
Recommended Configuration on Directly
Connected Uplink Switch for Cisco Switch Macro
interface FastEthernet0/1
switchport trunk encapsulation dot1q
switchport trunk native vlan 20
switchport mode trunk
mls qos trust cos
auto qos voip trust
macro description cisco-switch
spanning-tree link-type point-to-point