Networking crisis :o)

[tgalati4]

If lsmod doesn't show ipv6 then it's not loaded. Could be a network card problem or cable problem. Reseat your cables. Check for rat bites.

[dimitriv]

Hi

Thanks for all your support with this, we must get this fixed this weekend

Here’s a summary of the problem and actions taken:
• Ubuntu upgraded from 8.1-9.1 all successful, except internet access broken
• PPPOE Modem is attached and lights indicate connected to ISP, connection problem exists between PC to Modem


The resolv.conf was modified to include nameservers as below
gksudo gedit /etc/resolv.conf

# Generated by NetworkManager
nameserver 8.8.8.8
nameserver 8.8.4.4

Interfaces was checked satisfactorily for the setting below
gksudo gedit /etc/network/interfaces

auto lo
iface lo inet loopback

Netstat & ping generate as below
~$ netstat -r
Destination Gateway Genmask Flags MSS Window iritt Iface

[no other data]

ping www.google.com
ping: unknown host www.google.com

I tried one other step – is this doing harm, should I reverse this out?
However, since i've been pretty keen to find a resolution I tried these steps although i'm not sure if that was the right thing to do? If not please advise and i'll undo each of step
http://www.ubuntugeek.com/how-to-set...10-karmic.html


Manual IP
I’ve tried manually editing the connection and entering an IP (should be DHCP, don’t know what that DHCP address is) and copied subnet mask and gateway settings from my other pc/modem connected to same isp.


Routing table
tgalati4, suggested my routing table is messed up (and non existent).

It should look like:

tgalati4@tpad-Gloria7 ~ $ netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
link-local * 255.255.255.0 U 0 0 0 eth1
169.254.0.0 * 255.255.0.0 U 0 0 0 eth1
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth1

How do I create that routing table?

Blacklist
cat /etc/modprobe.d/blacklist.conf

Add the line:

# blacklist ipv6
blacklist ipv6

sudo nano /etc/modprobe.d/blacklist.conf


Disabling IPV6

I followed the instructions here
http://en.kioskea.net/faq/759-ubuntu...g-ipv6-support

For the instructions for 9.1, this line did not exist
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”
i tried manually entering this with the disable flag but but the output of
ps -ef | grep ipv6

continues to show ipv6

*(the output below)
jon 2536 2466 0 20:03 pts/0 00:00:00 grep ipv6

I also tried editing the file /etc/modprobe.d/blacklist
the file was blank initially, I entered the line specified
but after both of these changes the output was as above*

what's the correct method to disable ipv6 on 9.1?

Outputs from
~$ netstat -r

~$ ifconfig

are in previous post #17

Ping results are still ‘unknown host’

Modem Cable
The modem cable is correctly inserted, there are no rat bites or damage etc.

Please provide any additional ideas based on the above, or new suggestions

Thank you in advance

[tgalati4]

You have ipv6 disabled. The entry that you see is your grep search on "ipv6" so that's normal.

You can manually add a routing table:

man route

sudo route add default gw 192.168.1.1

netstat -r

ping www.google.com

Your IP address for your gateway may be different (such as 192.168.0.1, or some other address).

[dimitriv]

hi tgalati4

when i tried entering an add route, or running a copy of the command you gave in your last post I get
SIOCADDRT: No such process

I've search the forum and haven't found a suitable resolution yet.
I've just got these 3 lines to add routes for completing this

link-local * 255.255.255.0 U 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth0

thank you

[tgalati4]

Try to boot from a live cd using an older version of ubuntu. See if your network comes up.