Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: DNS not working.

  1. #1
    Join Date
    Nov 2010
    Beans
    7

    Question DNS not working.

    I'am using static IP configuration for my home NAS, running Ubuntu server 9.04 and I'am having trouble with dns resolve. While all configurations seems to be fine, it's fail to resolve any dns name.

    Here is my /etc/resolv.conf:
    Code:
    nameserver 208.67.222.222
    nameserver 208.67.220.220
    I'am able to ping those IPs:
    Code:
    PING 208.67.222.222 (208.67.222.222) 56(84) bytes of data.
    64 bytes from 208.67.222.222: icmp_seq=1 ttl=58 time=324 ms
    64 bytes from 208.67.222.222: icmp_seq=2 ttl=58 time=241 ms
    64 bytes from 208.67.222.222: icmp_seq=3 ttl=58 time=263 ms
    But:
    Code:
    dima@nas:~$ nslookup www.google.com
    ;; connection timed out; no servers could be reached
    Or:
    Code:
    dima@nas:~$ ping www.google.com
    ping: unknown host www.google.com
    Any ideas what's wrong?

  2. #2
    Join Date
    Nov 2008
    Beans
    555
    Distro
    Ubuntu 10.04 Lucid Lynx

    Re: DNS not working.

    Chose network icon upper right panel and choose Edit connections and tab ipv4... and put in the google nameserver 8.8.8.8

  3. #3
    Join Date
    Nov 2010
    Beans
    7

    Re: DNS not working.

    Quote Originally Posted by uncaspi View Post
    Chose network icon upper right panel and choose Edit connections and tab ipv4... and put in the google nameserver 8.8.8.8
    As i've mentioned in my first post i'am using ubuntu sever, so there is no GUI (no upper right panel), just ssh access.
    And I've tried Google DNS, they aren't working too.

  4. #4
    Join Date
    Apr 2010
    Beans
    327

    Red face Re: DNS not working.

    Quote Originally Posted by dmitriyap View Post
    I'am using static IP configuration for my home NAS, running Ubuntu server 9.04 and I'am having trouble with dns resolve. While all configurations seems to be fine, it's fail to resolve any dns name.

    Here is my /etc/resolv.conf:
    Code:
    nameserver 208.67.222.222
    nameserver 208.67.220.220
    I'am able to ping those IPs:
    Code:
    PING 208.67.222.222 (208.67.222.222) 56(84) bytes of data.
    64 bytes from 208.67.222.222: icmp_seq=1 ttl=58 time=324 ms
    64 bytes from 208.67.222.222: icmp_seq=2 ttl=58 time=241 ms
    64 bytes from 208.67.222.222: icmp_seq=3 ttl=58 time=263 ms
    But:
    Code:
    dima@nas:~$ nslookup www.google.com
    ;; connection timed out; no servers could be reached
    Or:
    Code:
    dima@nas:~$ ping www.google.com
    ping: unknown host www.google.com
    Any ideas what's wrong?
    Before you do anything, List your routing tables. Also check your firewall to see if its blocking DNS.

  5. #5
    Join Date
    Nov 2010
    Beans
    7

    Re: DNS not working.

    Here is my netstat -rn:


    Code:
    Destination Gateway Genmask Flags MSS Window irtt Iface
    192.168.0.0     0.0.0.0         255.255.255.0   U         0 0          0 eth0
    0.0.0.0         192.168.0.1     0.0.0.0         UG        0 0          0 eth0
    Firewall not blocking DNS

  6. #6
    Join Date
    Jun 2010
    Location
    asoko
    Beans
    834
    Distro
    Ubuntu

    Re: DNS not working.

    are you sure the firewall is not a problem? remember, dns is stateless so you need a return rule unless you are allowing all ports.

  7. #7
    Join Date
    Nov 2010
    Beans
    7

    Re: DNS not working.

    Quote Originally Posted by endotherm View Post
    are you sure the firewall is not a problem? remember, dns is stateless so you need a return rule unless you are allowing all ports.
    Could you give instruction commands to check this for me to be sure.

  8. #8
    Join Date
    Jun 2010
    Location
    asoko
    Beans
    834
    Distro
    Ubuntu

    Re: DNS not working.

    check the output of
    Code:
    sudo iptables --list
    and see if you have rules applied. if you do, then you will need to confirm that you have an allow rule for udp/53 inbound.

  9. #9
    Join Date
    Nov 2010
    Beans
    7

    Re: DNS not working.

    Quote Originally Posted by endotherm View Post
    check the output of
    Code:
    sudo iptables --list
    and see if you have rules applied. if you do, then you will need to confirm that you have an allow rule for udp/53 inbound.
    Code:
    Chain INPUT (policy ACCEPT)
    target     prot opt source               destination
    
    Chain FORWARD (policy ACCEPT)
    target     prot opt source               destination
    
    Chain OUTPUT (policy ACCEPT)
    target     prot opt source               destination
    All the rules are empty

  10. #10
    Join Date
    Apr 2010
    Beans
    327

    Re: DNS not working.

    Quote Originally Posted by dmitriyap View Post
    Code:
    Chain INPUT (policy ACCEPT)
    target     prot opt source               destination
    
    Chain FORWARD (policy ACCEPT)
    target     prot opt source               destination
    
    Chain OUTPUT (policy ACCEPT)
    target     prot opt source               destination
    All the rules are empty
    Im assuming that you are behind a router. Your firewall is basically turned off. Its allowing all. Reset your router and modem and then turn on the computer.

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

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