DHCP and Dyndns Problems

Discussion in 'Windows Small Business Server' started by Jacob van Iwaarden, Aug 28, 2011.

  1. Hello NG, I am pretty new in this scene, but I think I have some interesting
    problems. One of them is this:
    In the company we have anSBS2008 installed, a Router for Internet-Access, it
    works all fine.

    I have the same configuration at home with a second Licence, this one works
    fine too.
    Both Servers are named: SBS-1.

    Then I configured Dyndns on the Router. We can reach our system (and the
    network) using MyDom1.dyndns.org.
    The same was done at home with MyDom2.DynDNS.org.

    So far so good, I wanted to check the DHCP-Server and now it´s getting
    On my server at home, I have in the DHCP an entry: SBS-1.MyDom2.local, as it
    should be. I can configure the Network and the leases.
    In the Company this entry is called: MyDom1.dyndns.org and it is marked red.
    The server Never was told, there is a Dyndns entry somewhere. This was
    managed by the router! (In this case a Fritz!box, at Home I use a Draytek)
    I can delete the entry and connect to an authorized server,
    sbs-1.MyDom2.local. This one is then listed, but in the moment I select it,
    I get it red marked again...
    If I try searching, I enter the name, SBS-1, check the name, it is named
    correct. If I confirm, I get an entry in the DHCP-Console named
    MyDom1.dyndns.org!!! If I selct it, it is marked red again.

    The system works, but I cannot change anything in the configuration. That´s
    worrying me.

    Anyvbody who has an Idea? Can I deinstall and reinstall the DHCP wiith no
    problems/ danger?
    Any other Solution?

    Thanks in advance,
    Jacob van Iwaarden, Aug 28, 2011
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  2. Jacob van Iwaarden

    Brian Cryer Guest

    DynDns and DHCP should be completly unrelated.

    My suspision is that either:

    1. Your router is acting as a DHCP server. The only reason I can think of
    for why the DHCP server won't start is if it detects another one.

    2. You are VPN'ing to this server to configure it. (I can't think why else
    DynDns is a factor.) Ordinarily this should be fine, but if you are VPN'ing
    from a network with an SBS server I wonder whether that might be causing you
    a problem.

    Could you check also that the IP address of your server is static - it isn't
    trying to assign an IP address using a DHCP server - this also might account
    for where the DynDns name is coming from but I'm just speculating. At the
    same time check that your DNS server is your SBS box and not the router.
    Brian Cryer, Aug 30, 2011
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  3. Hello Bryan,
    thanks for your answer. I checked and answered your questions below. I know,
    I had a mistake in the beginning, I deaktivated the Router-DHCP while
    installing the SBS, but somehow it was aktivated for a few minutes later.
    The DHCP from my SBS is working, no doubt, but: I can not configure it ;-((


    ----- Original Message -----
    From: "Brian Cryer" <>
    Newsgroups: microsoft.public.windows.server.sbs
    Sent: Tuesday, August 30, 2011 6:22 PM
    Subject: Re: DHCP and Dyndns Problems

    My router was activateed as a DHCP-Server for a short while ;-(
    I found out very fast, that there was a problem in the network and
    deaktivated the Router-DHCP.
    Yea, I connect the server via VPN, but:
    The adress for external is a dyndns-Address, which reaches the router. This
    will pass the packets (based on the Ports used) through to the server, using
    an internal IP-Adress. So the server will get a VPN-Tunnel to extern but the
    IP-Adress he sees, is in his own network. (I checked)
    Yes the server has got a static IP-Adress. And it was not changed at all.
    Jacob van Iwaarden, Sep 4, 2011
  4. Jacob van Iwaarden

    Brian Cryer Guest

    Do you have these issues if instead of VPN'ing you RDC to the server? That
    way you are eliminating any issues that might be a hang-over of using a VPN
    connection (such as dyndns creeping into the name). To RDC you will need to
    open tcp port 3389 in your firewall and point it to the server.
    Alternatively VPN and then RDC over the top is probably just as good. When
    you RDC do any of your issues remain?
    Brian Cryer

    Brian Cryer, Sep 5, 2011
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