GRE Tunnel or mGRE tunnel ?

[Dipesh Patel]

Dear Experts,

Please find the Topology.

Based on it which will be the best suitable : 1. Point to Point GRE tunnel  2. Point to Multi-Point GRE Tunnel at DR1 and DR2.

How the Ruting should be if I want to use BGP over GRE Tunnel Interface?

GRE Tunnel will be used for only DC-DR replication . Rest traffic will move via MPLS link.

Regards

[Karsten Iwen]

Are there only these small amount of sites or do you plan to add many more in the future? With a small amount of tunnels I always prefer point-to-point-tunnels between all sites as they give you more control. With mGRE you need an additional layer of configuration like NHRP to map the next-hop. If there is no scalability-problem I try to avoid these additional steps to keep it simple where possible. But if the amounts of sites increase there is a real configuration-benefit in using mGRE-tunnels.

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[Dipesh Patel]

So in my case also P2P GRE tunnel is good.

Can we use BGP with GRE Tunnel for selected traffic only?

How?

Regards

[Karsten Iwen]

Can we use BGP with GRE Tunnel for selected traffic only?

You can use the GRE-tunnel nearly like a normal interface. BGP which is using unicast-communication is no problem, but you can also send multicast-traffic through the tunnel for your IGP. Filtering of traffic is done as usual with in- and outgoing ACLs.

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Don't stop after you've improved your network! Improve the world by lending money to the working poor:
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