1 server, 2 nic's in 2 networks

Discussion in 'Installation/Configuration' started by Jorem, Feb 8, 2009.

  1. Jorem

    Jorem Member

    Is it possible to have the first nic in one network and the second nic in another network?

    I need to move a server from one network to another and change the DNS settings to the new ip addresses.
    If have the two cables of the different networks to the server now. I think it might be the easiest way to transfer the server is to connect to both networks, change the dns to the news ip's. And everything keeps running then. Is that going to work?

    Thanks for your help :).
  2. falko

    falko Super Moderator ISPConfig Developer

    Yes, that's possible.
  3. Jorem

    Jorem Member

    Still trying to get this to work.

    Both network have a different gateway. After a search here and google I found that I had to add allow-hotplug to the network card config to function.
    I can access the internet now from the server en can reach the first network card. But I can not reach the second network card (wth the other gateway).

    What can I do to have both network cards work and an be reached from the internet? allow-hotplug setting maybe?

    Thanks for your help.
  4. falko

    falko Super Moderator ISPConfig Developer

    What are the outputs of
    route -nee

    What's in /etc/network/interfaces?
  5. tebokkel

    tebokkel New Member

    I don't think you'll get this to work, without explicit (and thus specific) routing, a load balancer or teaming solutions. At least I can't think of any way..

  6. Jorem

    Jorem Member

    @Falko: I have nothing in the interfaces yet. Tried it, but did not work, so put everything to the way it was.

    @tebokkel: I tried yesterday but did not get it to work. I'm looking for another solution now.

    Secundary DNS on the old location witch sends the traffic to the new location. Is that going to work?
  7. tebokkel

    tebokkel New Member

    DNS has probably not to do much with this problem.

    Is the server involved in a IP-address range migration in your organisation? If so, normally putting the new address as an extra address on the same interface is sufficient. If it's a move/migration to a new physical network, there is going to be a moment on which you flip the switch. Getting it to work simultaniously is probably not worth the effort.

  8. Jorem

    Jorem Member

    I have to move the server to another network. But both network cables reach my server.

    Currunt/"old" network:


    I have primary and secondary DNS server running on this system. I would like to move to the new network without much downtime (or only a few hours at night).

    2 networks on one server is not going to work :(. So my plan now was to put a temp server in the old location with the secondary DNS running witch will send the traffic to the new ip. Than I can change the primary DNS to the new ip and change it at my registrar. After 2 days I will change the secondary DNS to the new ip and everything runs on the new ip adresses.

    Is that a good way to do it? Or is there an easier/better way.
  9. tebokkel

    tebokkel New Member

    Hmm.. that changes things.

    I would choose to put up some old box on the new IP, where the /etc/bind files are copied. I don't know how your zone files are administered, but if you keep that on your production box, it shouldn't matter, as long as you keep that in sync (of course adapt nameservers as needed on the temp box).

    When the time comes, just move the box to the new IP, discarding the old settings. Change the DNS-server addresses to the new IP and you should be done (with the DNS server that is).
    Remember, it's only DNS: you should have (at least) two authoritive servers and you cannot controle the other and public DNS-servers, so there will always be some failure at some clients site (some dumb administrators cache DNS-entries for 7 days, even if the TTL or refresh is 1 second).

  10. Jorem

    Jorem Member

    Thanks Paul, Bedankt Paul :)

    I will try to setup a temp box on the new ip's and start moving some less important domains. Just to give it a go and see what happens.

    I let you know what happens. Maybe I can make a nice guide for other people who have to move their servers to another network.

Share This Page