Cisco Catalyst 4500 Series, Software Configuration Manual

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35-8
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 35 Configuring Layer 3 Interfaces
Configuring VLANs as Layer 3 Interfaces
Building configuration...
Current configuration : !
interface Vlan2
ip address 10.1.1.1 255.255.255.248
!
ip classless
no ip http server
!
!line con 0
line aux 0
line vty 0 4
!
end
Configuring VLANs as Layer 3 Interfaces
This section consists of the following subsections:
• Configuring SVI Autostate Exclude, page 35-8
•
Configuring IP MTU Sizes, page 35-9
• Configuring Layer 3 Interface Counters, page 35-11
Configuring SVI Autostate Exclude
Note The SVI Autostate Exclude feature is enabled by default and is synchronized with the STP state.
The SVI Autostate Exclude feature shuts down (or brings up) the Layer 3 interfaces of a switch when
the following port configuration changes occur:
•
When the last port on a VLAN goes down, the Layer 3 interface on that VLAN is shut down
(SVI- autostated).
• When the first port on the VLAN is brought back up, the Layer 3 interface on the VLAN that was
previously shut down is brought up.
SVI Autostate Exclude enables you to exclude the access ports and trunks in defining the status of the
SVI (up or down) even if it belongs to the same VLAN. If the excluded access port and trunk is in up
state and other ports are in down state in the VLAN, the SVI state is changed to down.
To make the SVI state up, at least one port in the VLAN should be up and not excluded. This action helps
to exclude the monitoring port status when you are determining the status of the SVI.
To apply SVI Autostate Exclude, perform this task:
Command Purpose
Step 1
Switch# configure terminal
Enters global configuration mode.
Step 2
Switch(config)# interface interface-id
Enters interface configuration mode.
Step 3
Switch(config-if)# switchport autostate exclude
Excludes the access ports and trunks in defining the
status of an SVI (up or down).
Step 4
Switch(config)#
end
Exits configuration mode.