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Dual/Redundant PEs


Has anyone implemented dual PE scenario for MPLS VPNs?

I am looking at a scenario where we can configure a single CE, via logical interfaces to connect to an access ring terminating on two different PEs.

Has anyone tried something like this and can point to some specific configurations?





Re: Dual/Redundant PEs

HI Sultan, [Pls Rate if HELPS]

If my understanding is not wrong on your Question. VRF usage is mandatory.

IF the Customer is under same VRF cloud means its very much possible. Any-how the Physical Interface is going to be connected with an Acccess Ring as per your requirement. The Access Ring will involve the Switch for the L2 Path transmit.

Create a Sub - interface on each MPLS-VPN-PE and 2" sub - interface on CE. The VLAN ID to be allowed on the overall L2 Path if its an L2 MPLS Customer. The "ip vrf forwarding " to be configured on the Sub - interfaces on the PE Side.

Hence your request is approached.

Hope I am informative.

Pls Rate if HELPS

Best Regards,

Guru Prasad R

Cisco Employee

Re: Dual/Redundant PEs

Hi Sultan,

There are various providers, who have implemented redundant CE access to a MPLS L3VPN network. Just be aware, that this requires special attention to possible routing loops with RIP, EIGRP or eBGP with as-override configured. You need to set SoO properly in those special cases. With static, OSPF and eBGP without as-override as PE-CE protocols you are fine.

Some info can be found in the IP routing config guides. Have a look at:

"Multipath Load Sharing eBGP/IBGP in MPLS-VPN"

and "EIGRP MPLS VPN PE-CE Site of Origin (SoO)"

In case this does not answer all your questions, please post your additional concerns.

Hope this helps! Please use the rating system.

Regards, Martin

New Member

Re: Dual/Redundant PEs

Hi Guruprasad and Martin,

Thanks for your responses, which have been helpful.

I think I should explain my setup a little... what I have is a CE connected to an access ring made of 3560 dual homed to a pair 7606 (I will be running MSTP in the access ring).

Each 7606 (PE) is connected to a 7604 (P). I have this between 2 cities over two different STM-16 backbones connected via pair of "P" routers.

The above setup is sufficient for scenarios where I want to have redundant backbone, "P" and access ring.

The problem is for redundant PE routers, (MSTP in the access, hence cannot do load sharing) my idea was to have HSRP sessions on both the PEs per logical CE-PE /30s, ofcourse there has to be VRFs on both the PE routers.

Will be using only static or eBGP between CE-PE.

Please suggest.