Quick basic question about routing

[schadmin]

If we have the following network:

router2*********router1

******|-------------|****

**********|************

********switch*********

**********|************

********router3********

If we have eigrp set up between all of the routers then if router1's LAN needed to talk to router2's LAN would the packets go all the way to Router3? Or would the switch be able to see the mac associated with the other interface IP and just switch it from there? Any insight would greatly help :)

[Richard Burts]

Ken

I can not tell from the drawing what the topology really is. It appears that there are 3 routers and 1 switch. Is that correct? It would also help to know if there are VLANs configured.

If I am right that there are 3 routers and 1 switch would it be the case that the routers share a VLAN in the switch (and therefore all 3 router interfaces are in the same subnet)? If so then packets would go from router1 to router2 without needing to go through rouer3.

If I have not understood the topology correctly then perhaps you could clarify it.

[edit: while I was writing my response you changed the drawing and it is now somewhat more clear that there is indeed 3 routers and 1 switch. It is still not clear if they are connected in a common subnet or in different subnets. I suspect that they are in a common subnet and therefore my original answer stands. router1 should communicate directly with router2 without needing to go through router3.

If I do not have it quite right, it would be helpful if you would give us a list of each interface and its IP address on each router. Also if you could give us the EIGRP configuration.]

HTH

Rick