Virtual Routing and Forwarding ” VRF “

This is a quick remember for me, i will redo this section in more details soon.

VRF   “VPN Routing and Forwarding”
VRF is used to isolate different clients, sites, etc… each vrf have its own routing table. Without MPLS it is called VRF-LITE.
Creation of the instance :
config#ip vrf “name”
Configure the interfaces :
Config-if# ip vrf forwarding “name”
Verify the config :
Show ip route ( you shouldnt see any route from the vrf instances )
Show ip route vrf “name”

for routing  you need to specify the instance ex :
Router ospf 1 vrf “name”
Router ospf 2 vrf “name2”
etc…

VRF-LITE
Creation of the instance :
config#ip vrf “name”
Creation of the Route Distinguisher “RD” under the vrf instance
config-vrf# rd ASN:NN ( it can be anything )
config-vrf# route-target export / import ASN:NN

Inter-VRF Routing VRF-LITE before 15.2 IOS
do not forget to enable “capability vrf-lite” globally or on the routing configuration section.
just need to redistribute into ospf and bgp the routes.

Inter-VRF Routing VRF-LITE after 15.2 IOS
No more need to use BGP, we just need to use the new command under the vrf instance :
config-vrf#route-target ASN:NN

 

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