GRE Tunnel help needed

Unanswered Question
Nov 24th, 2008


i have 2 routers connected to the internet (live ip on ethernet interface)

they both have different service providers hence diff ip pools..

i need to connect them so the LAN on each side can access the other LAN . INTERNET 124.x.x.(Router2)

i have made a vurtual tunnel on each of them with ips and respectively.

can any1 plz help..

I have this problem too.
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vishwancc Mon, 11/24/2008 - 02:40


Create a Gre tunnel using outside interface of the routers and use a routing protocol to advertise the LAN network

and you will be able to access the LAN network on both ends.

Thats my suggestion lets wait what other say.



John Blakley Mon, 11/24/2008 - 06:26

You'll set your tunnel interfaces up with a tunnel destination (your other routers ip).

You then create your crypto maps and apply them to the tunnel interfaces (or the public interface - I've seen Cisco do it both ways). Then you can run EIGRP over the tunnel. If you have an access list on the public interface blocking incoming traffic, you need to allow gre, esp, and udp 500 through from your other router.

In your EIGRP process, you'll create your network for your private side.

router eigrp 100

no auto-summary


Should work, but this is all from memory. I also found this which should explain in greater detail for you.


zaidumer Tue, 11/25/2008 - 01:47

thanks both of you.. the link seems interesting .. though il have to modify it a bit cause cant use dynamic routing.. have to set the routed statically..

i have the main hub router connected to the regional office in singapore as well (also using gre with ipsec ) so that is already mapped to the tunnel1 and physical..

i think i have no option but to use the same crypto map wth a diff seq # for my 3 branches via tunnel 2 3 & 4

will let you know if this works..


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