Routing Problem on 2801 IOS 12.4(15T1): Can ping Odd IPs, Cant ping Even IP

edwardwaithaka · ‎09-25-2007

Hi,

I have a very funny but irritating problem with my routing.

I have a branch router on IOS12.4(15T1) which has a default to the Core/HQ. From the Branch router, I can ping all the subnets in the HQ. From a PC connected to the router through a switch, I can ping "some" IPs in the HQ. eg take like subnet 10.1.1.0/24, I can ping .1, .3, .5 etc but can't ping .2, .4, .6 etc.

It is strange because, if it was a routing problem, then I shouldnt ping any IP.

Any leads?

Thanks,

Edd.

paul.matthews · ‎09-26-2007

Hi Edd, First, check for any access lists, second from the router local to the target network, can you ping those IPs? Is there a possibility they just have not been used? Is there a possibility that someone has done something "clever" with DHCP and they allocate even addresses from one server and odd from another, but have got the default gateway wrong on the "even" server?