Why do not configure RD for VRF?

[wfqk]

Hi, Please see attached digram. there are two customers: Red and Blue. After the following configuration and routing config, Red1 and Red2 can ping each other. And Blue1 and Blue2 are the same. My question is why it do not need to configure RD for their VRF? Instead, MPLS always need to configure RD for VRF. Any one can explain it? Thank you

ISP(config)#ip vrf Red
ISP(config-vrf)#exit
ISP(config)#ip vrf Blue
ISP(config-vrf)#exit
ISP(config)#interface FastEthernet 0/0
ISP(config-if)#ip vrf forwarding Blue
ISP(config-if)#ip address 192.168.1.254 255.255.255.0
ISP(config-if)#ip vrf forwarding Red
ISP(config-if)#ip address 192.168.2.254 255.255.255.0
ISP(config)#interface FastEthernet 2/0
ISP(config-if)#ip vrf forwarding Blue
ISP(config-if)#ip address 192.168.3.254 255.255.255.0
ISP(config)#interface FastEthernet 3/0
ISP(config-if)#ip vrf forwarding Red
ISP(config-if)#ip address 192.168.4.254 255.255.255.0

[willwetherman]

Hi,


From my understanding the RD value is only used in MPLS VPN deployments. It can be configured when deploying VRF lite but it’s not prepended to IPv4 prefixes that are either in the RIB or advertised between routers so it doesnt seem to do anything.

Here is a great discussion that explains the purpose of the RD

https://supportforums.cisco.com/discussion/11278831/real-purpose-route-distinguishers

Hope this helps