Dual NIC Routing

Discussion in 'Server Networking' started by Lee, Jan 7, 2008.

  1. Lee

    Lee Guest

    I have a 2003 SBS Server with 2 nic cards one configured on one network and
    the other on a different network. I have installed the RRAS and enabled it
    for LAN routing. what else do I need to do to get the server to route
    between the 2 cards?
     
    Lee, Jan 7, 2008
    #1
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  2. Robert L. \(MS-MVP\), Jan 7, 2008
    #2
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  3. Lee

    Bill Grant Guest

    That is a very bad idea. Using a DC as a router is always a bad idea. It
    will cause you all sorts of problems. Use some other device as your router.

    Routing between two subnets is easy if there is no other router
    involved. But if one subnet already has a routed connection (such as an
    Internet connection) it won't work without some extra work.

    Here is the simple case which just works.

    192.168.21.x dg 92.168.21.1
    |
    192.168.21.1 dg blank
    router
    192.168.31.1 dg blank
    |
    192.168.31.x dg 192.168.31.1

    Here is a common setup which won't work.

    Internet
    |
    gateway router
    192.168.21.1
    |
    workstations
    192.168.21.x dg 192.168.21.1
    |
    192.168.21.254 dg 192.168.21.1
    router
    192.168.31.1 dg blank
    |
    192.168.31.x dg 192.168.31.1

    This doesn't work because the default gateway for the 192.168.21 subnet
    is the gateway router, not the internal router. To route between the subnets
    you need extra routing on the gateway router to "bounce" local traffic to
    the internal router.
     
    Bill Grant, Jan 7, 2008
    #3
  4. In
    Hence a static entry. :)

    Maybe he means he wants to NAT?


    --
    Regards,
    Ace

    This posting is provided "AS-IS" with no warranties or guarantees and
    confers no rights.

    Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT,
    MVP Microsoft MVP - Directory Services
    Microsoft Certified Trainer

    Infinite Diversities in Infinite Combinations
     
    Ace Fekay [MVP], Jan 8, 2008
    #4
  5. Lee

    Bill Grant Guest

    Maybe he does, but then it won't route between the two subnets, because
    one is on the "public" side of the NAT. It will give the "new" subnet
    Internet access. We will have to wait for more info from the OP.
     
    Bill Grant, Jan 8, 2008
    #5
  6. In
    True, even if NAT'd, he won't be able to add another subnet without a static
    route. Maybe the original poster can shed some light on this. In the
    meantime, here is a static route example I drew up in the past for my
    students. Hopefully it will help him and others out.

    http://fekay.com/SupportBlogs/StaticRouteExample.htm

    Ace
     
    Ace Fekay [MVP], Jan 9, 2008
    #6
  7. Lee

    Lee Guest

    Well bad idea or not it has to be done, and SBS documentation suggests this
    very scenario. so regardless...
    Primary NIC Card 192.168.3.103 has gateway 192.168.3.7 which is the internet
    and routes its traffic to the internet and works as expected. Now add
    secondary NIC 192.168.5.103 (note the 5). Now I need to add the static
    entries to RRAS to get the "5" subnet to the "3" subnet and the internet, and
    visa versa the 3 sub net to the "5" subnet. I would expect entries in RRas to
    get the "5" subnet to the "3" subnet and the internet, and perhaps entries in
    the internet router to bounce the "5" subnet back somehow... ?????
     
    Lee, Jan 9, 2008
    #7
  8. Lee

    Bill Grant Guest

    No, you don't need to add any routes to the RRAS router. That isn't
    where the routing problem is. You have to add the route(s) to the Internet
    router. The new subnet can get to LAN 1 machines and the Internet router by
    default routing. Getting back is the problem and needs a static route on the
    Internet router because its default route is out to the Internet.

    Internet
    |
    gateway router
    192.168.3.7
    |
    LAN 1 machines
    |
    192.168.3.x dg 192.168.3.7
    |
    192.168.3.103 dg 192.168.3.7
    RRAS
    192.168.5103 dg blank
    |
    LAN 2 machines
    192.168.5.x dg 192.168.5.103

    The Internet router needs a static route to forward traffic for
    192.168.5 to the RRAS router. This is required for both traffic coming from
    the Internet and for traffic from LAN 1 (which goes to the gateway by
    default and needs to be bounced to the RRAS router).

    A ststic route like 192.168.5.0 255.255.255.0 192.168.3.103 on the
    gateway router should get it working if the RRAS router has LAN routing
    enabled.
     
    Bill Grant, Jan 10, 2008
    #8
  9. Lee

    Lee Guest

    Yes and thanks, I figured that out after a little playing around.

    FYI it would be nice if when replying to these that the original text be
    deleted so that only the reply is visible. AND if anyone at "headquarters" is
    reading. How about changing the code for the site so that the original
    message is not automatically placed in the reply.
     
    Lee, Jan 10, 2008
    #9
  10. Lee

    Bill Grant Guest

    That has nothing to do with the site. It is a setting in each user's
    newreader, and many people would be very upset if they could not see the
    complete conversation.
     
    Bill Grant, Jan 10, 2008
    #10
  11. In
    You're the first to complaing about not snipping out text. I usually hear
    complaints about bottom posting vs top posting.

    I find it useful to at least see what someone is replying to and would be
    netetiquette.. Sometimes when folks snip the whole thing as you are doing,
    they may be replying to a different post in the thread and their answer
    makes no sense. If I see what they were replying to, then it would make
    sense. Keeping the whole thread in a post is of course no netetiquette.

    I like to snip the extraneous and only leave what I am replying to. This
    makes more sense.
    http://www.velocityreviews.com/forums/t221488-snip.html

    I have a friend of mine that when I send an email, I get a reply without the
    original text. Sometimes we get in this long conversation thru email and may
    reply back wioth additional information before I hear a reply and I will get
    a reply back that I am not sure if is a response to the first or second
    reply. That drives me crazy and have to ask her what she was replying to.
    She uses AOL mail and it automatically snips everything.

    Here's an old thread from years ago that I was involved in you can read up
    on that involves bottom/top posting, another topic some bring up besides
    snipping:
    http://www.webservertalk.com/message158190.html

    But then again, each to their own.

    Ace
     
    Ace Fekay [MVP], Jan 10, 2008
    #11
  12. * Ace Fekay [MVP] (Wed, 9 Jan 2008 23:38:58 -0500)
    Definitely. And most reasonable people agree about that (at least
    those who care about communication). Top versus bottom posting is
    simply a question or preference to read the whole thing "in
    order"/chronologically. Reading the answer before the question is a
    bit weird for human beings.

    Thorsten
     
    Thorsten Kampe, Jan 10, 2008
    #12
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