no route to default gateway

Question

I just lost about all my hair on this one:

I got

• an ubuntu 12.04 machine on ip address 192.168.0.100, gateway 192.168.0.1
• A router on 192.168.0.1, running a forwarding dns
• ping 192.168.0.1 - or any ip address on the net works

but resolving doesn't work.

• ping www.google.com

  unknown host www.google.com
  

• route -n

  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  0.0.0.0         192.168.0.1     0.0.0.0         UG    100    0        0 eth0
  169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0
  192.168.0.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0
  

• ifconfig

  eth0      Link encap:Ethernet  HWaddr 22:ab:01:01:77:86
            inet addr:192.168.0.100  Bcast:192.168.0.255  Mask:255.255.255.0
            inet6 addr: fe80::20ab:1ff:fe01:7786/64 Scope:Link
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:443 errors:0 dropped:0 overruns:0 frame:0
            TX packets:426 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000
            RX bytes:34620 (34.6 KB)  TX bytes:64400 (64.4 KB)
            Interrupt:32
  

• telnet 192.168.0.1 53

  Trying 192.168.0.1...
  telnet: Unable to connect to remote host: No route to host
  

What the heck is going on ?

Solution

Firewall on the router was blocking access to port :53 Added

-A RH-Firewall-1-INPUT -p udp -m state --state NEW -m udp --dport 53 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 53 -j ACCEPT

Sorry for the hassle (and thanks sejo for helping out !)

Comments

[user128296]

check your /etc/resolv.conf file weather it contains nameserver's detatil or not.

[Tonny]

So I was right all along in my comment above :-)