NTL cable modem and Belkin router

Discussion in 'Broadband' started by Martin Underwood, Nov 19, 2005.

  1. A customer has bought a Belkin router which she wants to add to her existing
    NTL cable modem so as to share the connection between two PCs.

    In view of sections in the Belkin manual, I'm slightly puzzled as to what is
    needed to make the two work together.

    The modem is labelled "ntl:home 120, 60194E-A12" and the Belkin router is
    labelled " N10117 / F5D5231-4 / Ver 1100".

    The modem has Ethernet output to the PC and the router has Ethernet input
    (on the WAN side) and four Ethernet outputs (on the LAN side).

    Is it as simple as connecting the router's WAN socket to the modem's output
    by non-crossover patch cable and then connecting the computers by patch
    cables to the router's LAN sockets? I would have thought so, but there are
    statements in the router's manual about configuring broadband username and
    password for PPPoE. Does this suggest that the router's WAN port sends the
    usename and password to the modem so the modem can authenticate with
    broadband, possibility mimicking something that the PC does at present when
    directly connected to the modem?

    Unfortunately I didn't have time to try a simple connect-and-go approach
    when I visited the customer to investigate another problem.
    Martin Underwood, Nov 19, 2005
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  2. Martin Underwood

    Leigh Albon Guest

    I have this router, all I did was connect the WAN port to my cable modem
    (ntl 250) and the PC to one of the 4 Ethernet ports on the router, then just
    switched everything on and it all worked fine, obviously you then log into
    the router and configure the firewall, and port forwarding etc bit that's
    all I had to do.

    Leigh Albon, Nov 19, 2005
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  3. Martin Underwood

    Yddap Guest

    Yup all straight forward as Leigh said
    I use Belkin +Blueyonder modem
    NB all cat5 connection cables are straight Through
    Yddap, Nov 19, 2005
  4. I'm not familiar with the specific models, but I am familiar with the
    I have a similar box (from a different supplier) which has those
    things plus wireless. I'll use it as an analogy to answer your
    Yes, that's the idea. Are there some LEDs which will show whether you
    have been successful at this level? Until that's working, nothing
    else much is going to be any use.

    Once the PC has a working Ethernet to the LAN side of the router and
    (if you're using the default settings) has got itself assigned an
    address on the private network via DHCP from the router (this address
    might be 192.168.x.y for some values of x and y), then it should be
    possible to open a web browser and talk to the router at 192.168.x.1
    (same x as before. googling seems to suggest that your box will
    default to x=2).
    me too
    AFAIK you don't need that for the kind of NTL cable connection which
    presents an Ethernet interface.

    Mine has a pulldown for connection type, which can be
    [ DHCP Client or Fixed IP ]
    [ PPPoE ]
    [ PPTP ]

    When you're looking at the router management web pages with a web
    browser, there probably will be some kind of Help menu that might tell
    you a bit more about what the router expects.

    My hunch is that you're looking for the first of these options, in
    which case the PPPoE user name and password are irrelevant.

    There's something in the help information about setting a MAC address
    if instructed by the provider. Maybe someone who's on NTL will tell
    you about that part.
    Alan J. Flavell, Nov 19, 2005
  5. Martin Underwood

    Rob Morley Guest

    PPPoE is an ADSL thing.
    Rob Morley, Nov 19, 2005
  6. I have precisely the same setup, but with a router model number F5D5230-4,
    which must be an earlier version of the same router. Paraphrasing the
    (excellent) instruction book, the stages are:

    1. obtain ISP and network info (MAC address, IP address, host name and network
    settings. There's a space in the manual to write them down.
    2. Power down everything and connect computers to router. Connect WAN port to
    3. Turn on modem. Connect power to router. Check routers WAN Link light is on.
    4. Turn on each computer and when they have booted up check the LAN Link
    lights are on.
    5. Set up TCP/IP and file sharing on each computer (long discourse omitted).
    You can use the Belkin CD for this or do it by hand.
    6. Configure router for internet connection (set ISPs to "never dial a
    connection", "use proxy server" etc. (explanation omitted).
    7. Access the router (the IP address of mine is You can then
    select dynamic or static IP address and clone the MAC address.
    8. Enjoy.

    If you need it, there's a reset button on the back of the router.

    I've probably given you much more than you need. As a beginner I found the
    Belkin manual and set-up software excellent.
    Jock Mackirdy, Nov 19, 2005
  7. Martin Underwood

    Mugwump Guest

    For NTL you no longer need to clone the MAC address.
    Mugwump, Nov 19, 2005
  8. Martin Underwood

    Kraftee Guest

    In this case I think all you'll need to do is turn everything off,
    'plumb' it together (output from CM to WAN port & attatch the computer
    to one of the LAN ports), turn on CM & wait for it to link, turn on
    router & let it synch & then turn on the PC, no worrying about PPOE etc.

    Once it's connected together & working then you can play with some of
    the settings but it should be as simple as what I stated..
    Kraftee, Nov 19, 2005
  9. Nearly. You will need to power everything off, then power on the
    modem, wait around 30 seconds, then power on the router, wait another
    30 secs, then power on a PC. The router should get an IP addy from
    ntl, your pc from the router. If you don't power on in the right order
    nothing will happen, as ntl won't recognise the router and give it an
    Only relevant if the WAN port is for an ADSL connection. You are
    /sure/ the router's WAN port is ethernet?
    Mark McIntyre, Nov 19, 2005
  10. not required for ntl - they allow at least 3 CPEs with different MACs
    at any one installation (though not simultaneously of course, thats
    why you need a router).
    Mark McIntyre, Nov 19, 2005
  11. Jock Mackirdy wrote in
    I only had a couple of minutes to glance at the manual - it was one of those
    "oh, while you're here" jobs ;-) I presumed it would be as simple as
    everyone's described, but was worried by that section about PPPoE and
    username/password. If I'd looked a bit more closely (and if I'd taken my
    brain out of power-saving mode and realised that PPPoE only relates to ADSL
    and not cable), I'd have known that I had to ignore that section!

    Thanks for the suggestion about switching on in the correct order:

    - modem (wait 30 seconds)
    - router (wait seconds)
    - first PC

    I'll mention that to the customer: hope she remembers to do it in that
    order. I dare say she'll leave modem and router turned on permanently. The
    difficulty comes if they get switched off due to a power cut or as a
    precaution during a storm... I hope it will be obvious from the lights,
    without needing to teach her what to look for in ipconfig!

    I presume that the router's firewall rules are set to allow http (80) and
    email (25/110) traffic through by default, and to allow unlimited LAN (PC to
    PC) traffic.
    Martin Underwood, Nov 19, 2005
  12. Martin Underwood

    Leigh Albon Guest

    When the landlord has to turn power to the building off for maintanance and
    i am not here, i just turn the pc back on, the modem and router have come
    back on together with the power, and everything works fine

    Leigh Albon, Nov 19, 2005
  13. Martin Underwood

    Kraftee Guest

    Actually it's not. The reason you need a router is that NTL only
    provide 1 IP adress for each connection, that's the reason you need a
    router (& not just a switch/hub)
    Kraftee, Nov 19, 2005
  14. Yes, but I think basically you're both saying the same thing, since if
    there's only one IP address at the IP level, it can only be associated
    with one MAC address at the media level.

    If you need more, then that MAC address and IP has to be used as your
    gateway, and any other interfaces have to be behind some kind of
    router function - which would conveniently and safely be done with a
    router box, as is being discussed here.

    In earlier times we'd have used one of the computers as a gateway,
    running router software in the background to service the other
    computers, as well as being a normal computer at the same time. But
    that has its risks and complications, so, with router boxes being so
    cheap now, it would seem crazy not to use one.

    The question of how many different MAC addresses the ISP is willing to
    recognise (but only one at a time) must have some other basis (do they
    use the MAC address as a form of identification or authentication?).

    Alan J. Flavell, Nov 19, 2005
  15. Martin Underwood

    Kraftee Guest

    NTL uses the MAC of the modem/set top box (are they still using them) as
    authentication, which is the reason why you can't/shouldn't be able to
    take your CM around to another NTL customer & use it instead of theirs.
    Kraftee, Nov 20, 2005
  16. Martin Underwood

    stephen Guest

    i did this recently when i upgraded my router to a 802.11g version

    the only complication i got (with a set top box, so may be different with a
    cable modem) is that PCs going via a new device dont get unlimited access
    until i register the MAC address in a self help web page - just about any
    web access attempt takes you there

    you need the original account name + password / pin to log in and sort this.
    stephen, Nov 20, 2005
  17. This isn't a problem - once ntl have initially recognised the router's
    MAC, and assigned it an IP, you don't need to worry about the above
    palaver on subsequent reboots. The 30secs wait the first time is to
    allow the router and ntl's servers to have a chat about getting an IP
    sorted out and the MAC recorded in some database. Subsequent times,
    just let everything come online after the power outage, and it'll
    'just work'.
    More likely its set to allow EVERYTHING through by default - most
    routers come configured with the f/w off.
    Mark McIntyre, Nov 20, 2005
  18. Actually it is.
    We're saying the same thing. I just couldn't be bothered with the full
    explanation. The point I was making is that at leat three different
    MACs can simultaneously be in ntl's database and hence no need to
    clone MACs.
    Mark McIntyre, Nov 20, 2005
  19. Once upon a time, the cable companies allowed only one MAC. I believe
    this was a form of authentication / security. If you changed NIC or
    PC, you had to call them to register the new MAC.
    Mark McIntyre, Nov 20, 2005
  20. Since we're talking about a NAT router, I would *hope* that the
    default is to allow anything to go *out*, but only to route related
    traffic back *in*.
    Alan J. Flavell, Nov 20, 2005
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