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Webcast-Catalyst9k

Multiple GRE Tunnels

I am attempting to set up multiple GRE tunnels from a host to nine remote sites. The host has an Adtran 904E router and the remotes have Cisco 891 and 887s

I am using 192.168.10.1 255.255.255.0 and 192.168.10.2 255.255.255.0 for the inside tunnel addresses. When I go to set up the second tunnel on the same interface using 192.168.10.3 255.255.255.0 and 192.168.10.4 255.255.255 0, I get a subnet error.

How should these tunnels be addressed?

Many thanks in advance.                 

3 REPLIES
VIP Super Bronze

Multiple GRE Tunnels

Try putting each each tunnel in a separate subnet

tunnel-1 192.168.10.1 255.255.255.0 and 10.2

tunnel-2 192.168.11.1 255.255.255.0 and 11.2

HTH

Super Bronze

Re: Multiple GRE Tunnels

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Posting

"Regular" GRE tunnels are usually configured at p2p, i.e. with a /30 or /31.  They can be configured with larger IP blocks, wasting IP space, but that will work fine as long as the address spaces don't overlay.

If you want multiple sites to share the same subnet, they you'll want to implement MGRE.  Then you can use the IP addressing as you intended.

New Member

Re: Multiple GRE Tunnels

All your 4 address belongs to the same /24 network, in this case you should use a /30 subnet.

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