ISP changed thier platform, now my dhcp client won't work

Unanswered Question
Jun 23rd, 2008


I am running a Cisco 2600 router, it's been working just fine for a long time.

Last week my ISP changed thier configuration, now my Cisco box won't gather an IP address over DHCP. I looked at the debug output, and the discover is not getting a response. I also plugged the Cisco box onto my LAN to let it talk to my local DHCP server, which works just fine. Could there be something wrong with my router? I've attached the debug info.


Martin Swain

I have this problem too.
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Paolo Bevilacqua Mon, 06/23/2008 - 08:48

Unfortunately certain versions of IOS have an issue with the dhcp client that cannot get an address.

Check if upgrading IOS to latest helps, but if it doesn't, I'm afraid there's no remedy.

martinswain Mon, 06/23/2008 - 08:54


Can you provide some more info, maybe a link or reference? My Cisco box talks to my local DHCP server just fine, but not my ISP's DHCP server.


Martin Swain

Paolo Bevilacqua Mon, 06/23/2008 - 08:58

I have no link to provide because the problem is not even documented as far as I know.

My theory is that some incompatibility exists between certain dhcp servers (not all and not the cisco ones, but for sure some used by ISPs) and the IOS dhcp client, so no matter what the configuration, cisco will never take an address.


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