MPLS L3 VPN Questions

Hey Guys,

       I'm just trying to get a better understanding of how to build these
MPLS VPN's properly and I guess the documentation and INE workbook just
confuses me a little bit. So if anyone can assist me that would be great.

Like Denzel in the movie Philadelphia. Explain it to me like I'm a 6 year
old.

1. When defining the VRF's between two PE routers.

Example

R1

Step 1 - Create VRF locally on R1

ip vrf VPN_A

 rd 100:1 <---- ROUTE DISTINGUISHER (This is locally significant to R1 and
add's a 8 byte value to IPV4 prefix to create a VPNIPV4 prefix. )

Step 2 - Assign Route-Target command
 route-target both 100:1 <----- allows routing information from to traverse
from R1 VPN_A to R2 VPN_A thru their connected interfaces and import/export
routing information.

R1 <----------> R2

int fa0/1 (R1)
 ip vrf forwarding VPN_A
 ip add 10.1.1.1 255.255.255.0

R2

Step 1 - Create VRF locally on R2

ip vrf VPN_A

 rd 100:1 <---- ROUTE DISTINGUISHER (This is locally significant to R2 and
add's a 8 byte value to IPV4 prefix to create a VPNIPV4 prefix. )

Step 2 - Assign Route-Target command
 route-target both 100:1 <----- allows routing information from to traverse
from R2 VPN_A to R1 VPN_A thru their connected interfaces and import/export
routing information.

Question - Does the route-target have to match the route distinguisher on
both ends. if the route-target is say 100:2 and the route distinguisher is
100:1 on VPN_A this technically shouldn't work
across the VPN correct.

R2 <----------> R1

int fa0/1 (R2)
 ip vrf forwarding VPN_A
 ip add 10.1.1.2 255.255.255.0

thanks

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Received on Fri Jun 03 2011 - 10:01:11 ART