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3005 Concentrator, GRE

I have remote sites with a backup link via VPN from a router at the remote site to a PIX firewall at the main site.

There are GRE tunnels configured from the remote site routers to 4503 switches behind the firewalls at the main site.

There are a couple of the sites that the GRE tunnels just drop out with no indication as to why.

I want to try and isolate the problem by configuring the VPN to terminate to a 3005 concentrator at the main site, then reconfigure the GRE tunnels to go through the concentrator.

Is this feasable to do?

I worked on this a little today and could not get the GRE tunnels to come up.

It looked like the VPN was good, but the tunnels would not come up (I have keepalives configured).

This should be no problem conceptiually correct?

Cisco Employee

Re: 3005 Concentrator, GRE


You are correct. Conceptually, I dont see a problem. As far as the GRE Source and Destination IP Addresses are part of the interesting traffic between the VPN Servers, the IPSEC Tunnel as well as the GRE Tunnel should work fine.

Below is an URL that discusses a similar scenario with the Pix Firewall.

I hope it helps.



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