Strange Networking issue

[dabrowne]

I have a strange networking issue. I can ping anything on my subnet, but can't seem to get much beyond that. I can't resolve DNS names, but I can get a response from google's IP (74.125.226.32). That's the part that confuses me. If it was a subnet or DNS issue it wouldn't appear like this. This only happened once I upgraded from 11.10 to 12.04. Does anyone have any suggestions?
Thanks

[papibe]

Hi dabrowne.

Could you post the result of these commands?

ifconfig

route -n

nslookup ubuntu.com

grep dnsmasq /etc/NetworkManager/NetworkManager.conf

cat /var/run/nm-dns-dnsmasq.conf

Regards.

[dabrowne]

Thanks for the reply Papibe.

ifconfig

eth0 Link encap:Ethernet HWaddr 00:07:e9:43:58:a9
inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::207:e9ff:fe43:58a9/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:10102 errors:0 dropped:0 overruns:0 frame:0
TX packets:6087 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1335040 (1.3 MB) TX bytes:3059339 (3.0 MB)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:3589 errors:0 dropped:0 overruns:0 frame:0
TX packets:3589 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:402570 (402.5 KB) TX bytes:402570 (402.5 KB)

route -n:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.1.2 0.0.0.0 UG 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0
192.168.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0

nslookup ubuntu.com:
;; connection timed out; no servers could be reached


grep dnsmasq /etc/NetworkManager/NetworkManager.conf
dns=dnsmasq

cat /var/run/nm-dns-dnsmasq.conf
server=192.168.0.1


My network is DHCP'd and my other boxes (Windows, Smart TV, Phones) all function correctly. Not sure what happened to my Ubuntu box.

Thanks again

[papibe]

It looks like dnsmasq is not working properly. Check if disable it solve the problem.

Follow this steps. After that, make sure the file /etc/resolv.conf contain a line like this:

nameserver 192.168.0.1

Hope it helps, and tell us how it goes.

Regards.

[dabrowne]

Thanks again.
My resolv.conf file now says:

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 192.168.0.1
search gateway.2wire.net

However, nothing was being resolved. I pulled the DNS addresses from my ISP and manually entered them and it all seems to be working. It's strange, because I tried this earlier with Google's public DNS servers and had no luck. So, disabling dnsmasq must have fixed something, but not everything. I can look into the local DNS issue, but the panic is off now that my box can connect to the outside world.
Thank you so much for your help.