Windows 2003 server causes router to crash

Discussion in 'Server Networking' started by Grizelli, Feb 26, 2005.

  1. Grizelli

    Grizelli Guest

    Newbie here. I have just set up a 2003 server on my network and it causes
    the ADSL router (a USR 9003) to crash at random intervals. The router is
    normally rock solid, and performs flawlessly with the server shut down. The
    server is running DNS, the router provides DHCP and firewall. I can't see
    anything obvious that would cause this, any clues on where I should be
    looking? Many thanks
    Grizelli, Feb 26, 2005
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  2. Grizelli

    Herb Martin Guest

    There is really nothing that the server can DO to the
    router that isn't a BUG on the router (and nothing
    much likely that it can do even then.)

    Replace the router or upgrade the firmware if that
    is possible.
    Two DHCP servers might interfere with each other
    but that would affect the clients and not likely cause
    one to crash.

    DNS is a passive services (clients must ask it a

    BTW, chances are that you need to take a look at
    the DHCP on the router anyway to make sure it
    is NOT giving out it's own (or an ISP) DNS server
    My thinking would be something odd about the
    routers NIC or arp tables finding a bug in their
    code when the server is online (extra entry, odd
    response to particular MAC adddress, some
    weirdness in the wiring.)
    Herb Martin, Feb 26, 2005
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  3. Grizelli

    Grizelli Guest

    Many thanks Herb, I'll take another look a the things that you suggest.
    Different PCs come and go on the network all the time and don't cause this
    problem, so I find it hard to beleive that the router has an inherent fault
    of some kind - its been running fine for around a year, and the problem has
    only appeared with the arrival of the server, and it disappears if the server
    is shut down. I'm struggling :-(

    Grizelli, Feb 26, 2005
  4. Grizelli

    Jeff Cochran Guest

    I'm assuming your server is a static IP and it and the router are not
    the same IP. Also that the router DHCP doesn't have the server IP in
    its scope.

    Jeff Cochran, Feb 26, 2005
  5. Grizelli

    Herb Martin Guest

    Let's make it really simple: By definition if
    you can crash that router by sending it something
    on the network then the router has a bug.

    Routers should AT LEAST survive whatever
    traffic they are asked to handle.
    Herb Martin, Feb 27, 2005
  6. Grizelli

    Herb Martin Guest

    I'm assuming your server is a static IP and it and the router are not
    Now that is an interesting idea -- years
    ago it was not uncommon for some (UNIX)
    systems to crash on duplicate addresses.

    Still a bug on the router or any machine that
    does this but that might account for it.
    Herb Martin, Feb 27, 2005
  7. Grizelli

    Grizelli Guest

    Can't argue with that. I'm going to try the idea of taking the server
    address out of the DHCP scope and see if it solves the problem. Thanks for
    all the suggestions, I'll report back later.

    Grizelli, Feb 27, 2005
  8. Grizelli

    Herb Martin Guest

    Well, the router/DHCP should not be
    giving out an address in use anyway.

    (Some -- e.g., MS -- probe first so maybe
    the bug is in THAT part of the router code.)
    Herb Martin, Feb 27, 2005
  9. Grizelli

    Grizelli Guest

    Well, as expected, it ain't the DHCP/address. The crash seems to happen
    after a number of hours, around 3 or 4, and mostly when there are no live
    internet connections going on, but can't see anything in the server activity
    logs to identify a possible event that might be the cause. I've killed AD
    and restarted the server, lets see if that highlights where the problem with
    the router is. More later...

    Grizelli, Feb 27, 2005
  10. Grizelli

    Herb Martin Guest

    "Killing AD" or looking in the server logs
    is NOT going to solve you problem with this

    It is just silly to focus on AD for such a problem.

    Upgrade the firmware on the router or seek help
    from the router newsgroups/help desk.
    Herb Martin, Feb 28, 2005
  11. Grizelli

    Grizelli Guest

    What seems silly to you appears logical to me. The router worked fine before
    introducing the server (and specifically, Active Directory, as the problem
    doesn't appear with AD turned off), therefore something in AD is the cause of
    the problem. Whether it is some strangeness in AD, or a mistake on my part in
    configuring it, is what I next intend to find out. I realise that the router
    should not fall over under normal conditions, but clearly something that the
    server is doing is making it upset. Until I find out what that something is,
    there's not much point in binning the router and replacing it with another (I
    already have the latest software, and the USR support groups don't have any
    constructive suggestions).

    Thanks for your advice, I'll continue with a logical - though possibly
    'silly' - approach to finding the cause.

    Grizelli, Feb 28, 2005
  12. Grizelli

    Kerry Brown Guest

    I would use Network Monitor to capture packets between the server and the
    router. It will take a lot of digging, cross referencing packets to the time
    of the crash. If the router doesn't keep logs it may be impossible.

    Another possibility is electrical interference. Are the server and router
    located next to one another, on the same electrical circuit, same network
    switch or directly connected etc.

    Kerry Brown
    KDB Systems
    Kerry Brown, Feb 28, 2005
  13. Grizelli

    Herb Martin Guest

    No, it is a logical consideration at first
    thought, but knowing how routers work
    eliminates it as anything but a bug in the
    router -- or some hardware issue which
    again leads to a bug in the router.

    There should be NO packet that I can put
    through (to) a router that will crash it.

    It is NOT an AD problem -- even were you
    to show that it only happened when AD
    sent out a certain packet (which is really
    probably isn't sending through this router,
    except MAYBE DNS) it would still be a
    router bug.

    BTW, if AD is the Initiator (not the cause)
    then the most likely is that you have the DC
    set to use the "router" as it's DNS server
    (which is itself wrong) and the attempt to
    register the DC with DNS is where the router
    No, that that isn't completely clear.

    (Sure, it could be some weird electrical
    problem like when I add to many telephones,
    or certain types my TiVo fails to complete
    a download -- but since TiVo's modem passes
    a dial test, downloads the file, and fails during
    processing of the data it is really a TiVo bug,
    which I think they have finally fixed.)
    How much does this thing cost?
    It remains silly to remove AD from a DC due
    to something like this.

    Suggestion: Make sure ALL of your machines
    are set to use your INTERNAL DNS server,
    and this includes (especially the DNS server
    and DC itself):

    The above is correct in any case, but if this
    fixes the problem then it is likely the router
    is crashing when something attempts to register
    a dynamic DNS address (it should just refuse).

    DNS for AD
    1) Dynamic for the zone supporting AD
    2) All internal DNS clients NIC\IP properties must specify SOLELY
    that internal, dynamic DNS server (set.)
    3) DCs and even DNS servers are DNS clients too -- see #2
    4) If you have more than one Domain, every DNS server must
    be able to resolve ALL domains (either directly or indirectly)

    netdiag /fix

    ....or maybe:

    dcdiag /fix

    (Win2003 can do this from Support tools):
    nltest /dsregdns /server:DC-ServerNameGoesHere

    Ensure that DNS zones/domains are fully replicated to all DNS
    servers for that (internal) zone/domain.

    Also useful may be running DCDiag on each DC, sending the
    output to a text file, and searching for FAIL, ERROR, WARN.

    Single Label domain zone names are a problem Google:
    [ "SINGLE LABEL" domain names DNS 2000 | 2003 microsoft: ]
    Herb Martin, Feb 28, 2005
  14. Grizelli

    Kerry Brown Guest

    No, it is a logical consideration at first
    Of course it's probably a bug in the router. That doesn't mean it's not
    worthwhile tracking down what triggers the bug. There may be a workaround
    once the cause of the problem is found. At the very least the manufacturer
    may be able to update their firmware once the bug is found.

    Kerry Brown
    KDB Systems
    Kerry Brown, Feb 28, 2005
  15. Grizelli

    Herb Martin Guest

    Sure -- the silliness is doing things like uninstalling

    AD is not responsible.

    I agree with you that if the "server" is triggering
    this it stands a likelyhood of being some "electrical"
    or NIC issue.
    Herb Martin, Feb 28, 2005
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