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New Member

Tunnel Question.

I have set up a simple GRE tunnel. I can ping through the tunnel from the each end of the routers. What is the procedure to get hosts talking through it?

  • Other Network Infrastructure Subjects
1 ACCEPTED SOLUTION

Accepted Solutions
Gold

Re: Tunnel Question.

The default gateway on the hosts should point to the router's local interface address they are attached to. This shouldn't have anything to do with the tunnel (?). For instance:

host1---(e0)rtr1(to)------(t0)rtr2(e0)host2

It doesn't matter how the tunnel between rtr1 and rtr2 is set up, the default gateway on host 1 would be set to e0 on rtr1, and the default gateway on host2 would be set to e0 on rtr2.

Does that help? Or is there more in the network we don't see at this point that's confusing matters?

:-)

Russ.W

5 REPLIES
New Member

Re: Tunnel Question.

Hi,

You need to advertise the host via the GRE tunnel. You can run an IGP on your tunnel interfaces and advertise the host. When you do a " show ip route " to the host from Router B you need to make sure that the host is learned from the tunnel. Hope this helps.

New Member

Re: Tunnel Question.

I am currently running EIGRP on the routers. When I do a "show ip route" I do see the "tunnel" network advertised. I have never set up tunnel before so please forgive my ignorance with this subject.

Re: Tunnel Question.

Basically, if X and Y are the networks on which the hosts reside (one network at each end), then you need to advertise these networks under eigrp. Assume Z is the network on the tunnel interface.

Your config should look like

router 1 - config

router eigrp 100

network X

network Z

router 2 - config

router eigrp 100

network Y

network Z

Hope that helps.

New Member

Re: Tunnel Question.

The output you pointed out is how i am configured.

I believe the internal config (routers) are correct as I can ping either way. My biggest unknown is how to configure the hosts (ip..default gateway) so I can talk host to host via that tunnel.

Gold

Re: Tunnel Question.

The default gateway on the hosts should point to the router's local interface address they are attached to. This shouldn't have anything to do with the tunnel (?). For instance:

host1---(e0)rtr1(to)------(t0)rtr2(e0)host2

It doesn't matter how the tunnel between rtr1 and rtr2 is set up, the default gateway on host 1 would be set to e0 on rtr1, and the default gateway on host2 would be set to e0 on rtr2.

Does that help? Or is there more in the network we don't see at this point that's confusing matters?

:-)

Russ.W

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