Cisco Cisco IOS Software Release 12.4(4)T

VRF-aware DNS forwards queries to name servers using the VRF table. Because the same IP address 
can be associated with different DNS servers in different VRF domains, a separate list of name caches 
for each VRF is maintained. The DNS looks up the specific VRF name cache first, if a table has been 
specified, before sending a query to the VRF name server. All IP addresses obtained from a VRF-specific 
name cache are routed using the VRF table.

This section contains the following tasks:

 

 

Perform this task to define a VRF table and assign a name server.

A VRF-specific name cache is dynamically created if one does not exist whenever a VRF-specific name 
server is configured by using the ip name-server vrf command option or a permanent name entry is 
configured by using the ip host vrf command option. The VRF name cache is removed whenever all 
name server and permanent entries in the VRF are disabled.

It is possible that multiple name servers are configured with the same VRF name. The system will send 
queries to those servers in turn until any of them responds, starting with the server that sent a response 
the last time.

configure terminal

ip vrf vrf-name

rd route-distinguisher

ip name-server [vrf vrf-name] server-address1 [server-address2...server-address6]