What is VRF?

Question:

please explain me C2921-VSEC what is VRF also I have found that vrf can be configured on both router and switch. I have 3750 and 3800 so where should I configure vrf.

Answer:

VRFs in general used to virtualizes the routing tables where you can have multiple routing tables in one physical router
VRFs can be used with MP-BGP and MPLS for network like ISPs
also VRFs can be used locally to perform separation between multiple routing instances aka VRF lite
both can be used for Path isolation

useful links
http://packetlife.net/blog/2010/mar/29/inter-vrf-routing-vrf-lite/
http://www.cisco.com/en/US/docs/solutions/Enterprise/Network_Virtualization/PathIsol.html  C2951-VSEC

Original comes from http://switch.2329893.n4.nabble.com/3900-router-td14.html