dhcp-relay: ip helper address fails

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

  1. tgot

    tgot Guest


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



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

    conf t
    int eth0
    ip helper-address

    now, a testclient from the subnet requests an ip address but
    did not get one.
    i sniff the traffic on the 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.

    tgot, Feb 12, 2004
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  2. tgot

    PES Guest

    I would bet this is a bug in the IOS. I would try a different version.
    PES, Feb 13, 2004
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  3. I assume the server and the router aren't really both 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
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