Find the answer to your Linux question:
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 19
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1

    strange dhcp doesn't work

    Hello. I have Ubuntu 10.04.i have installed & configured dhcp3-server. Now i have problems with it. i've googled and searched in forums - nothing relevant.
    My dhcp3 -server assignes addresses to a computer with win7 on it (takes~1min though), win vista, but does't assign an address to another computer with ubuntu 10.04 and winxp. all these computers have common dhcp client configuration because they can obtain address from the same dhcp server (it's my internet provider ). I think the issue is in the client config in 10.04 and xp , but i want them to work with my dhcp server and with the internet provider dhcp server with the same configuration. all of the mentioned computers can get ip from my internet provider dhcp server.
    my config files and command results:
    eth0      Link encap:Ethernet  HWaddr 00:e0:4c:4c:70:21  
              inet addr:  Bcast:  Mask:
              inet6 addr: fe80::2e0:4cff:fe4c:7021/64 Scope:Link
              UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
              RX packets:759 errors:0 dropped:0 overruns:0 frame:0
              TX packets:37 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:1000 
              RX bytes:49978 (49.9 KB)  TX bytes:4648 (4.6 KB)
              Interrupt:12 Base address:0xd400 
    eth1      Link encap:Ethernet  HWaddr 00:e0:4c:a0:d8:a8  
              inet addr:  Bcast:  Mask:
              UP BROADCAST MULTICAST  MTU:1500  Metric:1
              RX packets:0 errors:0 dropped:0 overruns:0 frame:0
              TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:1000 
              RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
              Interrupt:10 Base address:0xd000 
    lo        Link encap:Local Loopback  
              inet addr:  Mask:
              inet6 addr: ::1/128 Scope:Host
              UP LOOPBACK RUNNING  MTU:16436  Metric:1
              RX packets:8 errors:0 dropped:0 overruns:0 frame:0
              TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:0 
              RX bytes:480 (480.0 B)  TX bytes:480 (480.0 B)
    ip address:
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet scope host lo
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
        link/ether 00:e0:4c:4c:70:21 brd ff:ff:ff:ff:ff:ff
        inet brd scope global eth0
        inet6 fe80::2e0:4cff:fe4c:7021/64 scope link 
           valid_lft forever preferred_lft forever
    3: eth1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
        link/ether 00:e0:4c:a0:d8:a8 brd ff:ff:ff:ff:ff:ff
        inet brd scope global eth1
    subnet netmask {
           interface eth1;
           option subnet-mask;
           option time-offset 100; 
           option domain-search "";
           option host-name "xer";
           option netbios-name-servers;
           option netbios-scope "qwery";
           option interface-mtu 1500;
           option ntp-servers;
           option domain-name-servers;
           option domain-name "";
           option routers;
           option broadcast-address;
    #       default-lease-time 600;
    #       max-lease-time 7200;
    dhcp3-server defaults:
    I want my 2-nd computer with winxp and 10.04 to get ip from my 1-st computer with dhcp3server just like it gets ip from my internet provider. please help

  2. #2
    Linux User ptkobe's Avatar
    Join Date
    Feb 2008
    Torres Vedras, PT
    all of the mentioned computers can get ip from my internet provider dhcp server.
    what usually happens is that your iprovider gives ONE ip to the router at your home, and that router has a dhcp server that gives local ip's to your computers.

    There can only be one dhcp server in a lan, and so your problem may be that. You will need to disable the router dhcp server.


  3. #3
    Have you tried "dumbing down" your dhcpd config file? Just make it as wide-open and simple as possible so that it will dish out an ip address and that's it.

    Also, have you tried running it in the foreground sending errors to STDOUT? Don't know if your version of the DHCP daemon supports that, but in case it does, might be worth a shot.

  4. $spacer_open
  5. #4
    ptkobe, when i test my inner network i disconnect from the provider network

  6. #5
    Linux User ptkobe's Avatar
    Join Date
    Feb 2008
    Torres Vedras, PT
    OK. So you disconnect from the provider, but do you disconnect from the router too? Again, the other dhcp is on the router.

    Give us more info on what you do (if you wish). You disconnect from the internet provider network (explain that you unplug this or turn off that), then you start your dhcp-server (you run the command...) and then you do what? (like reboot the other machines, restart networking on the linux box running $ sudo /etc/init.d/networking restart ?, etc...)

    Also I don't really understand the ip on eth0 and the local ip on eth1. It may help if you can explain how do you connect all those computers together and to the internet. Do you have a router or just a switch (or none)?

    Also, why do you say "all of the mentioned computers can get ip from my internet provider dhcp server"?

    Bottom line, I have dhcp3 with bind9 in my home and it works fine (4 ubuntu machines and one xp). Two dhcp may explain your symptoms, or maybe as you use two nic on (at least) one machine, may be a connection problem (physical). That's what comes to my mind.


    PS: Logs may also give important info. check with
    $ tail -200 /var/log/dhcpd.log
    Another important file (on your server and linux clients) is the /etc/network/interfaces file.

  7. #6
    # This file describes the network interfaces available on your system
    # and how to activate them. For more information, see interfaces(5).

    # The loopback network interface
    auto lo
    iface lo inet loopback

    # The primary network interface
    auto eth0
    iface eth0 inet dhcp

    #my second interface for dhcpd
    #perhaps i ought to use pointopoint option (see manpage for THIS file)
    auto eth1
    iface eth1 inet static

  8. #7
    description in the next post (i'm not allowed to post links and i can't make attachments so you'll have to copy the link rifght after the word "links") sorry for inconvenience
    Attached Images Attached Images
    Last edited by JudgeJosephDredd; 12-08-2011 at 02:00 PM.

  9. #8
    check out the link
    Last edited by JudgeJosephDredd; 12-08-2011 at 01:58 PM.

  10. #9
    Linux User ptkobe's Avatar
    Join Date
    Feb 2008
    Torres Vedras, PT
    First, I'm sorry about the delay. We had a holiday here and I was away from computers.

    Your server interfaces file it's ok, and I never use pointopoint option
    Your clients should have something like
    auto eth0
    iface eth0 inet dhcp

    Your physical schema didn't solve my doubts. See, you can't connect computers directly with a cable (unless it's a special cable, and even so only one to one). So, are you using plugs on the wall as you didn't mentioned any switch or router? The question is if so, how are you connecting your clients to your dhcp-server? A ordinary direct cable won't do it. And if not, how are you connecting all the computers together without a switch.

    during test I do a full network restart with
    $ sudo /etc/init.d/networking restart
    but I'm guessing sudo dhclient will be ok.

    Sorry but I can't still make a "educated" guess of what your problem could be. Maybe someone else in the forum is seeing something I could be missing?

    Hope you can understand my english. Regards

  11. #10
    All of the mentioned computers except the one with winxp/10.04 have their own hub in the room and each hub is connected to our Internet provider (3 hubs available). no router or switch is involved. to test my server i connect computers with a regular ethernet cable pic See, i just want my dhcp server to be connected to the internet and my winxp/10.04 computer be connected to my dhcp server. Other Computers ( win7 vista) are owned by my friends and have internet cable of their own, they are just used for testing. for test i connect ONE computer (winxp/10.04 OR vista OR win7) at a time to my server via standard ethernet cable.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts