Cisco Catalyst 4500 Series, Software Configuration Manual

Page: 2012 / 2086

83-10
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 83 Configuring Easy Virtual Network
About Easy Virtual Network
Command Inheritance on EVN Trunk Interfaces
One of the benefits of EVN is the ability to easily configure multiple EVNs on a common trunk interface
without the need to configure each interface associated with an EVN individually. An EVN trunk
interface takes advantage of the fact that the configuration requirements for different EVNs will be
similar over a single trunk interface. When specific commands are configured on the trunk interface, they
define default values that are inherited by all EVNs running over the same interface, including vnet
global. If you feel that the settings are acceptable for all of the EVNs sharing an interface, then no
individual configuration is necessary.
For example, the OSPF hello interval can be set for all EVNs over the trunk interface with the following
configuration:
interface gigabitethernet1/1/1
vnet trunk
ip address 10.1.2.1 255.255.255.0
! set OSPF hello interval for all VRFs on this interface.
ip ospf hello-interval 20
Overriding Command Inheritance Virtual Network Interface Mode
You can set up EVNs on the same trunk interface to have different configurations, by override inherited
values using specific commands in virtual network interface mode for individual EVNs. In this mode,
the command’s settings override the Cisco default value or the value you set in interface configuration
mode.
In interface configuration mode, entering the vnet name command causes the system to enter virtual
network interface mode.
Beginning in Cisco IOS XE Release 3.9.1E, you can override the inherited IP address for subinterfaces.
For more information, see
Changing the Inherited IP Address for Subinterfaces, page 83-17 .
The following list displays the commands for which inherited values can be overridden:
Command
Values Inherited by
EVNs on Interface? Values Can Be Overriden in Virtual
Network Interface Mode?
ip accounting Yes No
ip address Yes Yes
ip broadcast-address Yes No
ip directed broadcast Yes No
ip information-reply Yes No
ip irdp Yes No
ip load-sharing Yes No
ip mask-reply Yes No
ip mtu Yes No
ip proxy-arp Yes No
ip redirects Yes No