A-VPLS + IRB question on the Catalyst 6500/SUP2T

npritchett · ‎01-22-2016

I am considering the deployment of A-VPLS in combo with integrated routing and bridging (IRB) for a data center interconnect scenario. Reading through the explanation and example configuration in the documentation (such as in "Data Center Interconnect: Advanced Virtual Private LAN Service") there are a couple of points about it that are missing which I need clarification on.

(1) The example clearly shows how IRB would be configured at one MPLS-PE node. What is not clear to me is whether IRB may only be configured on one PE node for a given VLAN, or may it also be configured on the corresponding VLAN interfaces of the other PE nodes as well.

(2) If answer to above is yes, it is permissible to do IRB for a given VLAN at multiple nodes in the VPLS system, then may I also configure the same IP address on each of the IRB interfaces or must their IP addresses be different?

In other words, building off the example in the document cited above, if the following is configured on MPLS node "A"...

interface TenGigabitEthernet1/1/3/0
 ip address 10.1.1.1 255.255.255.0
 mpls ip
!
interface virtual-ethernet 1 
 transport vpls mesh
  neighbor 10.2.2.2 pw-class cl1
  neighbor 10.3.3.3 pw-class cl1
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 10, 20
!
Interface VLAN 10
 ip vrf forwarding vrf_1
 ip address 12.12.12.1 255.255.255.0
!
Interface VLAN 20
 ip vrf forwarding vrf_2
 ip address 12.12.11.1 255.255.255.0
end

...am I allowed to repeat the same IRB configuration of interfaces VLAN10 and VLAN20 on nodes "B" and "C", like thus:

interface TenGigabitEthernet1/1/6/0
 ip address 10.2.2.2 255.255.255.0
 mpls ip
!
interface virtual-ethernet 1 
 transport vpls mesh
  neighbor 10.1.1.1 pw-class cl1
  neighbor 10.3.3.3 pw-class cl1
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 10, 20
!
Interface VLAN 10
 ip vrf forwarding vrf_1
 ip address 12.12.12.1 255.255.255.0 ! Same IP address as node A's vlan 10 interface
!
Interface VLAN 20
 ip vrf forwarding vrf_2
 ip address 12.12.11.1 255.255.255.0 ! Same IP address as node A's vlan 20 interface
end

interface TenGigabitEthernet1/1/9/0
 ip address 10.3.3.3 255.255.255.0
 mpls ip
!
interface virtual-ethernet 1 
 transport vpls mesh
  neighbor 10.2.2.2 pw-class cl1
  neighbor 10.1.1.1 pw-class cl1
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 10, 20
!
Interface VLAN 10
 ip vrf forwarding vrf_1
 ip address 12.12.12.1 255.255.255.0 ! Same IP address as node A's vlan 10 interface
!
Interface VLAN 20
 ip vrf forwarding vrf_2
 ip address 12.12.11.1 255.255.255.0 ! Same IP address as node A's vlan 20 interface
end

Philip D'Ath · ‎01-24-2016

I see no one has responded to this yet.

Do you have a Cisco maintenance contract, like SmartNet? If so I would open a case with TAC and ask them. It would be great if you could post the answer back when you find out.