dhcp-relay: ip helper address fails

Discussion in 'Cisco' started by tgot, Feb 12, 2004.

  1. tgot

    tgot Guest

    hi

    we use a cisco 1605 (ios 11.2) with two ethernet interfaces.

    eth0:
    10.0.0.1

    eth1:
    172.16.0.1

    on the subnet 172.16.0.0 we have a dhcp-server (172.16.0.1)
    we also wanted to achieve that dhcp works on the 10.0.0.0 subnet, so
    we added an ip helper on interface eth0:

    conf t
    int eth0
    ip helper-address 172.16.0.1

    now, a testclient from the subnet 10.0.0.0 requests an ip address but
    did not get one.
    i sniff the traffic on the 172.16.0.0 subnet and saw that the router
    forwards the udp broadcast (port 67) to the dhcp server, but the
    router does not set the dhcp relay agent field, i think that is the
    problem why the client does not get a valid ip configuration.

    so, can anybody tell my what is wrong with this configuration.

    thanks
    thomas
     
    tgot, Feb 12, 2004
    #1
    1. Advertisements

  2. tgot

    PES Guest

    I would bet this is a bug in the IOS. I would try a different version.
     
    PES, Feb 13, 2004
    #2
    1. Advertisements

  3. I assume the server and the router aren't really both 172.16.0.1. You
    might check for the presence of "ip bootp server" in your config. That
    command enables the relay agent address filling in, and it was introduced
    in 11.2. You may either not have it yet, or it may not have been on by
    default then.
     
    Martin Gallagher, Feb 13, 2004
    #3
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.