Internet connection does not work after update.

[zoeken]

After 3 days of reading threads around here without any success i#ve decided to post a new thread.

Problem sounds like that:

I'm new ubunutu user, but i was happy with it for the last 6 months. Three days ago Update Manager asked for update. After update my network go crazy. When i start the computer i have network up and running but no internet. After some restarts (sometimes after one other times after more than one) everything is ok.
I've heard that problem can be from Network Manager, so ihave removed it and now i have Wicd. It's a little better because now from 10 starts i have only 2 ... 4 internet failure, before was very hard to get to the internet.
The system spec. are: Ubuntu HH 8.04 LTS on CPU AMD X2 3800+ with 2 Gb RAM, on board network RTL8111.

ifconfig output:
eth0 Link encap:Ethernet HWaddr 00:19:66:29:34:f7
inet addr:82.212.12.175 Bcast:82.212.13.255 Mask:255.255.254.0
inet6 addr: fe80::219:66ff:fe29:34f7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:140638 errors:0 dropped:0 overruns:0 frame:0
TX packets:4905 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:14642194 (13.9 MB) TX bytes:578583 (565.0 KB)
Interrupt:251 Base address:0x2000

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:4401 errors:0 dropped:0 overruns:0 frame:0
TX packets:4401 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:178485 (174.3 KB) TX bytes:178485 (174.3 KB)

The output from ifconfig command it's the same in both situation - internet works or it' not working. The only thing it changes is the IP. Internet connection it is made through a Cable Modem without a router.
If helps.... when i use the live DVD with Ubuntu internet works every time, so i believe it is not a hardware problem, but i don't want to reinstall Ubuntu again... it must be a solution! Anyone can help???


Regards!

[dollylamb]

try to ping your gateway then somewhere. If it works, i guess there's something wrong with your dns resolver.

[superprash2003]

post output of cat /etc/resolv.conf and type ping google.com and post output

[zoeken]

thanks for quick reply!

steve@steve-desktop:~$ ping www.google.com
ping: unknown host www.google.com

steve@steve-desktop:~$ ping 72.14.205.100
PING 72.14.205.100 (72.14.205.100) 56(84) bytes of data. ---- it seems that is the Ip for google.com
ping: sendmsg: Operation not permitted

cat /etc/resolv.conf - i suppose i have to try this when the internet does not work...Now the result is:
steve@steve-desktop:~$ cat /etc/resolv.conf
nameserver 91.89.89.91
nameserver 91.89.91.94

So that's the result from ping. In the latest 2 hours i have tried to manually set up the IP. It works great but i have dynamic IP so when my cable modem get another IP it is stop working. Now i'm testing another thing - only with DNS manually inserted. It works but i don't know for how many restart. Now i'm on the 5'th restart without any problem.

[zoeken]

From today on i'm a happy man = PROBLEM SOLVED!
Solution:

https://help.ubuntu.com/8.04/internet/C/troubleshooting.html#troubleshooting-ipv6

IPv6 Not Supported

1.IPv6 is supported by default in Ubuntu and can sometimes cause problems.
2.To disable it, open a Terminal (Applications → Accessories → Terminal) and type the command: gksudo gedit /etc/modprobe.d/aliases
3.Find the line alias net-pf-10 ipv6 and change it to read alias net-pf-10 off.
4.Reboot Ubuntu.



Yeah....
Problem com out again after ~20 good starts.....
I'm doomed! .... agian.....