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EIGRP urgent help needed

guys i am going nuts please help me out ......i have four routers A,b,c,d

router A B and C serials are in same AS XX....router D and C ethernet are in different AS AA.....all routers have loopback interfaces.....redistribution of eigrp is done on c router (between 2 AS).....now i can see a route to loopback of router d on router A and same on router D (i can see th eloopback route) with EX D......but when i ping the serial interface of router C from A.....i cant ping it ....its in same subnet though......the strange thing is when i ping the loopback of router D with the source ip of loopback A....i can ping it easily.....i m going nuts what is wrong....am i missing something.....please guys help me out as i have spend 4 hours top troubleshoot that.....thanks a million in advance...

7 REPLIES
New Member

Re: EIGRP urgent help needed

What networks are using....have you turn off auto-summary?

Hall of Fame Super Silver

Re: EIGRP urgent help needed

I am puzzled by this statement in the original post: "but when i ping the serial interface of router C from A.....i cant ping it ....its in same subnet though" Are you saying that the serial from A is really in the same subnet as the serial on C? It is not valid for the same subnet to exist in 2 different (isolated) places in the network.

This is not a problem with EIGRP but is a basic function of processing IP. If C is attempting to send a response and the destination address is in a subnet that appears to be local then C will attempt to send the response on the local subnet and it will never get to A. To get it to work you need the subnet of A to be different from the subnet of C.

HTH

Rick

Hall of Fame Super Blue

Re: EIGRP urgent help needed

Can you post

1) Configs of routers

2) "sh ip route" from each router

3) "sh ip eigrp neigh" from each router

Jon

New Member

Re: EIGRP urgent help needed

guys thanks for reply......now i will explain in more detail...

router A B C D

router A

router EIGRP XX

network 192.168.1.1 0.0.0.0 (loopback0)

network 192.168.2.1 0.0.0.0 (serial 0/0)

router B

router EIGRP XX

network 192.168.6.1 0.0.0.0 (loopback0)

network 192.168.2.2 0.0.0.0 (serial 0/0)

Router C

router eigrp XX 192.168.2.3 0.0.0.0 (serial 0)

router EiGRP BB

network 192.168.7.1 0.0.0.0 (loopback in eigrp BB not XX)

network 192.168.9.1 0.0.0.0 (ethernet ip)

router D

router EIGRP BB

network 192.168.10.1 0.0.0.0 (loopback 0)

network 192.168.9.2 0.0.0.0 (ethernet)

now to explain more: router A B C are connected via hub and spoke FR....where B is hub.

redistribution done on C

router EIGRP XX

redistribute eigrp BB metric 1500 2000 255 1 1500

router EIGRP BB

redistribute eigrp XX metric 1500 2000 255 1 1500

all loopbacks are /32

now when i do sh ip route command on router A

i can see the route towards loopback of router D with EX D which means that its from other AS....now problem

on router A i cant even ping router C interface serial one (whioh is in same subnet) i can ping the hub interface (router B)

now on router D i can see the route towards loopback of router A but i cant ping it from that side as well.....the funny thing is when i am on router A and i ping with extended command using loopback of router A (ping router D loopback) i can ping it....its v strange.....can someone explain as well......i have already put no split horzon on hub's interface.....i guess i have explained it this time....can someone please reply to it....thanks

one more thing when i do sh ip eigrp nei on router A i can only see router B not C.......

Hall of Fame Super Silver

Re: EIGRP urgent help needed

Explaining the topology helps. Given this additional information I would guess that the problem is that A has a mapping for B but does not have a mapping for C, and/or C has a mapping for B but not for A.

HTH

Rick

New Member

Re: EIGRP urgent help needed

hey rick can you please explain in detail....what i have to do to rectify the problem

Hall of Fame Super Silver

Re: EIGRP urgent help needed

If you show the frame relay map on A I believe that it will have a mapping of the address of B but will not have a mapping for the address of C. To make it work you would need to configure a frame relay map for the address of C and the PVC used to get to that address. And on C you would need to configure a frame relay map for the address of A and the PVC used to get to it.

HTH

Rick

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