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HSRP for PE redundancy

Hello Guys

I wanna to implement PE redundancy for CE devices on the access layer. We have l3vpn customers, VRFs are terminated on PE routers, so all the traffic going to CE devices is layer 2, except for some CE devices that are working in layer 3. So my goal is to provide PE-CE connections in a dual-home fashion from CE devices to aggregation layer. About STP on PE routers, we have configured MST and every PE router is the root bridge for its MST region.

I did some lab tests in gns3 using IOS routers, so everything looks work fine, however as you know we are not able able to test everything we want. I have some concerns:

- What is the best practice in order to allow STP BPDUs between each PE router and avoid layer 2 loops?

- What is the best practice using hsrp in a VRF environment, I mean we have many VRFs on the network, moreover hsrp supports 255 groups only. So how can I address this? is it a good recomendation use the same hsrp group for many VRFs? how might impact this? 

- What is the best practice to establish hsrp timers in order to achieve a sub-second convergence? I know that this depends on how the routing protocols are configured on the MPLS network and how they are synchronized as well.    

Finally I wanna to implement this on IOS and IOS XR PE routers.

Thanks for you support and advice!



Cisco Employee

For ASR9k you might want to

For ASR9k you might want to see link below.

Best Regards,