Trouble setting up Cisco-UBR924 with Comcast

Discussion in 'Cisco' started by cbbs70a, Nov 5, 2008.

  1. cbbs70a

    cbbs70a Guest

    After having more than one cable modem fail this year, I decided to
    go with something more sophisticated and picked up a Cisco-UBR924
    cable router. I picked that one because it runs IOS. For the life of
    me, I cannot get this thing to work with Comcast. Comcast is
    completely worthless on this issue. Essentially, the cable interface
    is up but the protocol goes up and down. Comcast says they can't "see"
    my MAC address. Something must be missing in my config. I thought that
    I could be missimg the following line, but the router does not
    recognize the command "cable-modem downstream saved channel xxxxxxx".
    This should be straightforward. Any help at all would be GREATLY
    appreciated. I need to get this working and I have no problem paying
    for help if necessary.
    This is an abbreviated config.

    interface Ethernet0
    ip address
    ip nat inside
    interface cable-modem0
    ip address docsis
    ip nat outside
    no cable-modem compliant bridge
    ip nat inside source list 1 interface Ethernet0 overload
    ip nat inside source static tcp 22 interface Ethernet0 22
    ip classless
    ip http server
    ip http cable-monitor advance
    access-list 1 permit
    cbbs70a, Nov 5, 2008
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  2. cbbs70a

    alexd Guest

    Do you have a 'dumber' cable modem you can test on the same circuit? IOW,
    have you eliminated your UBR 924 as the problem?
    alexd, Nov 5, 2008
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  3. cbbs70a

    bod43 Guest

    I dont know anything about cable really, but I have
    burned a lot of midnight oil on other broadband technologies.

    It appears that you will need to get Comcast to register
    the new modem's mac address. This will of course be irritating
    if you can't get it to work:), since the old modem will
    not work until you get them to put it back.
    It appears that you cannot change the mac address on the cisco.
    Maybe they will register both for a short time?

    There are some troubleshooting documents here:-
    bod43, Nov 5, 2008
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