Cable modem config page

Discussion in 'Server Networking' started by Dave Whyte, Jun 5, 2004.

  1. Dave Whyte

    Dave Whyte Guest

    Hi all,

    I have an SBS2003 installation with a soho nat router in between ISA Server
    and my cable modem.
    SBS (with two nic's) - Nat Router - Cable Modem

    Question is, how do I connect to the cable modem config web page that sits
    beyond the nat router?

    Thanks for any help

    Dave Whyte, Jun 5, 2004
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  2. I don't think you can unless you connect directly to the cable modem. What
    do you need to change? Your ISP may be able to do it for you.

    May I ask why you have two NICs if you're using a router?
    Lanwench [MVP - Exchange], Jun 5, 2004
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  3. Dave Whyte

    Dave Whyte Guest

    Because that is what you should do with ISA server and SBS. Remember ISA is
    on the SBS box so to service internal and external networking, you use two
    nic's one in the private range 192.168.x.x the other to the cable modem
    therefore seperating the two networks.


    "Lanwench [MVP - Exchange]"
    Dave Whyte, Jun 5, 2004
  4. Ah, sorry. I don't use ISA (it's not that I don't like it, I just support
    mostly single-server shops and don't like using my DC as a router/firewall -
    I'd happily run ISA on another server).

    Lanwench [MVP - Exchange], Jun 5, 2004
  5. Dave Whyte

    Dave Whyte Guest

    Thanks for the replies by the way.

    There is those two schools of thought. One says do not have any extras on
    the DC i.e. Exchange, ISA etc. The other is the SBS route. I come down on
    the latter to be honest and there is quite a lively SBS support community
    out there. It has a fan base basically who are very loyal to the product.
    After years of semi-neglect on Microsoft's part, they are now fully behind
    SBS and the people who sell and support the product.

    I am somehow stumped regarding the cable modem log webpage issue. I thought
    about port triggering/forwarding but I am not sure if that is the right way
    to go. I need to very rarely see the CM logs as and when there are speed
    issues with the connectin etc. This needs reported to the cable company who
    run a support newsgroup.
    I suppose I am being a bit belt and braces but once you get a tech problem
    in your head it is hard to shift until you fix it. Who was saying the word
    geek!! LOL :)


    "Lanwench [MVP - Exchange]"
    Dave Whyte, Jun 6, 2004
  6. I just started getting my feet wet with SBS 2003 Standard after years of
    abhoring SBS (very bad experiences with the 4.x version). It's all wizarded
    to death, admittedly, but isn't too bad thus far...seems to be good value
    for small offices/limited budgets. I still prefer not to rely on its ISA for
    network protection, and use an external firewall appliance instead....I'm
    fond of Sonicwalls.

    I imagine you could use both at once....but I don't see much value in
    turning a Windows server into a router, especially when it's your sole
    server/DC/Exchange/DNS/file&print/whatnot box. Resource load, security
    issues (I prefer to head things off before they get to the server/network at
    all). There are so many other, affordable options out there nowadays I don't
    see the point unless ISA is on a dedicated box.

    Same wariness about running SQL and Exchange on the same server, oy....first
    thing I did after installing SBS was to turn off everything I didn't need,
    and could turn off...
    I guess my question there is, why can't the cable company techs get into
    their modem themselves from the Internet? I don't see how you're going to
    access the modem unless you connect a machine directly to it.
    Not me, nosiree. ;-)
    Lanwench [MVP - Exchange], Jun 6, 2004
  7. Dave Whyte

    Bill Grant Guest

    That is true, but it doesn't explain the problem. If the server has one
    nic in the same IP subnet as the modem/router, why can't you contact the
    cable modem from the server? What IP addresses are you using on the "link"
    subnet between the server and the router?

    Bill Grant, Jun 6, 2004
  8. Dave Whyte

    Dave Whyte Guest

    Hi guys,

    The router is ip, nic connected to router, Cable
    Modem page

    Dave Whyte, Jun 6, 2004
  9. The router between the server and the cable modem is doing NAT.
    Lanwench [MVP - Exchange], Jun 6, 2004
  10. Dave Whyte

    Bill Grant Guest

    That's why I asked about the actual subnet addresses he was using. Why
    is it doing NAT if the cable modem has a private IP?

    "Lanwench [MVP - Exchange]"
    Bill Grant, Jun 7, 2004
  11. Guys!

    Cable Routers have "config pages" that at typically web based. Cable
    *Modems* do not! They do not even have addresses to make them accessable.
    They are really no more than a glorified "media converter". They aren't
    even really a Layer2 device although they are refered to that way,...they
    don't even have a MAC address to my knowledge. They just convert from the TV
    Cable to the Ethernet Cable and translate the signal, so they are more like
    Layer1 conversion devices.

    It sounds like you haven't described the topology very well. It sounds like
    you have created a "back-to-back dmz". If this is what you specifically
    wanted then fine, but if you simply stumbled into it or don't fully realize
    the implications of a "back-to-back dmz" then you should ditch the "router"
    and plug the Cable Modem directly into the external Nic of the ISA/SBS box
    using a crossover cable. You may already be using one of those between the
    Router and the Modem.


    Phillip Windell [MCP, MVP, CCNA]

    Phillip Windell, Jun 7, 2004
  12. Dave Whyte

    Dave Whyte Guest


    The cable modem in question is a Motorola Surfboard 4100. It has a mac
    address and an internal CM config page which if plugged straight into a pc
    with crossover is reached at It also has a public dynamic
    address given by the ISP.

    According to all SBS guru's, the best thing to do is to stick a soho nat
    router in between the 2nd nic and the broadband device. Have a look at and see my post there.

    I think I have found that age old "normal vs SBS way of doing things".
    All I want to do is type in the CM config page address and let the browser
    take me there to check signal levels etc.
    And yes, the cable company could check the config for me but they don't
    until I have a fault. When it does go wrong, they ask for details like
    signal strength etc which is given in guess where, yes the CM config page.

    I know it may look funny i.e. having a local address 2nd nic, to a Nat
    router then to a cable modem who's config page is also a local address, but
    that is the way of things. The CM does therefore act as a media converter.
    I do understand, and have explained the network topology as it lies.

    Thanks again,
    awaiting further contact :)

    Dave Whyte, Jun 8, 2004
  13. I checked on Motorola's site. The 4100 is no longer listed but the 4200 is.
    I looked at the PDF for setting it up. All I can say is "What a convoluted
    mess!!",...I don't have to worry about buying anything from them that is for
    sure. It appears to do DHCP and appears to act as a NAT box (soho
    router),..but only to a point, only has one LAN port and only supports
    up to 32 users (you have to use a separate hub or switch). So it appears
    after that point you'd have to add an additional NAT box to gain additional
    users, thereby creating a (probably unwanted) Back-to-Back DMZ between the
    NAT Box and the Motorola that many people running small networks don't
    understand or know how to deal with.
    Phillip Windell, Jun 8, 2004
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