Users Guide

VRF 1357
VRF Route Entries
Routes are shared among the VR instances. The number of routes supported
can never exceed the platform supported number. Initially, the number of
“free” routes is the platform supported maximum. “Free” routes are available
for any VR to use.
Two schemes are imposed on sharing of routes between the VR instances:
Reservation and Restriction. The administrator can use the maximum routes
command to reserve a number of routes for a VRF or to restrict the maximum
number of routes available to a VR instance.
Reserved routes are deducted from the “free” routes available in the system.
In-use routes are also deducted from the “free” routes available in the system.
The dynamic number of routes available to be allocated to a VRF instance is
the lower of the number of “free” routes available in the system and the
administrator-configured maximum routes.
The system-wide limit on static route entries is enforced on a per-VR-instance
basis. That is, each VRF may allocate the system limit of static routes.
VRF configuration follows the same steps as configuration for the default
routing instance with two additional steps: creating the VRF instance and
associating VLANs to the instance. Existing commands which have been
enabled for VRF accept an additional VRF instance identifier (name). VRF
names can be up to 32 characters in length. If a VRF instance identifier is not
used in the command, it applies to the global routing instance by default.
Follow the steps below to create a VRF and enable OSPF routing in the VRF:
First, create the VLAN instances associated to the VRF. It is recommended
that a VLAN numbering scheme be developed to allow for future growth and
to assist in the easy recognition of which VLANs are associated to which
VRFs.
1 In global config mode, create the pool of VLANs:
console#config
console(config)#vlan 100-109
console(config-vlan100-109)#exit
2 Assign the VLAN to an interface:
console(config)#interface gi1/0/1
console(config-if-Gi1/0/1)#switchport access vlan 100
console(config-if-Gi1/0/1)#exit