What if same VPNv4(prefix:rd) use in same MPLS? If RT can why vrf leak

[TangoAlfa]

Hi all,

Who can break this simple doubt for all? so that this thread can be helpful for all.

1) RD makes the prefix unique from other same prefix as VPNv4 for mpls . Now if the same VPNv4(prefix:RD) being use by another vrf in same MPLS what will happen in that case?

2) If RT Export and import  make possible for different VRF communication they why we need additional VRF leak policy, ACL all these stuff?

[MHM Cisco World · Accepted solution]

1) RD makes the prefix unique from other same prefix as VPNv4 for mpls . Now if the same VPNv4(prefix:RD) being use by another vrf in same MPLS what will happen in that case? if there is RR in your MPLS Core then one of them will select as best path and other will not advertise between PE.

2) If RT Export and import  make possible for different VRF communication they why we need additional VRF leak policy, ACL all these stuff? we need it if from VRF-A to VRF-B we need to leak specific route how we can do that, this can not done alone via Route-target, we need route-target and policy to filter which prefix will leak between two VRF.

[MHM Cisco World · Accepted solution]

1) RD makes the prefix unique from other same prefix as VPNv4 for mpls . Now if the same VPNv4(prefix:RD) being use by another vrf in same MPLS what will happen in that case? if there is RR in your MPLS Core then one of them will select as best path and other will not advertise between PE.

2) If RT Export and import  make possible for different VRF communication they why we need additional VRF leak policy, ACL all these stuff? we need it if from VRF-A to VRF-B we need to leak specific route how we can do that, this can not done alone via Route-target, we need route-target and policy to filter which prefix will leak between two VRF.

[TangoAlfa]

@MHM Cisco World Simple and nice explanation this what I expect. It will help many........