Cannot get ethernet working

[higgins]

Hi

I cannot get ethernet to connect via DHCP or manually after installing Ubuntu 9.04 using my network information:

Default Gateway - 192.168.1.254
Net Mask - 255.255.255.0
DNS - 192.168.1.254
IP Address - 192.168.1.5

I tried using the Live CD also and that does not work either.

Searching the forums I have gathered the following information from my equipment:

Active Network Connection

http://ubuntuforums.org/attachment.php?attachmentid=121602&stc=1&d=1247990919

ifconfig OUTPUT

http://ubuntuforums.org/attachment.php?attachmentid=121603&stc=1&d=1247990922

lspci output

http://ubuntuforums.org/attachment.php?attachmentid=121604&stc=1&d=1247990922

Any ideas on how I get this working?

[aesis05401]

How did you input the address information shown in your screenshots?

[higgins]

How did you input the address information shown in your screenshots?

I changed the connection type to manual and entered the information via the user interface while booted into the live CD

[Kraut~salat]

what exactly isn't working? You cannot connect to the Internet net thru a router, you cannot connect to the router, you don't get name resolution...?

please post the output of "netstat -rn"

Can you ping your gateway 192.168.1.254?

[aesis05401]

I changed the connection type to manual and entered the information via the user interface while booted into the live CD

K, provided the address you assigned is within your DHCP server parameters, you should be able open a terminal and type in :


sudo dhclient


This will cause your machine to broadcast a dhcp request with the IP address you assigned.

I do not use the gui to configure my network, but it sounds like you are not actually getting a lease (contacting the dhcp server), or there is something wrong with your address numbers.

Does this help?

[higgins]

what exactly isn't working?

Internet is not working


You cannot connect to the Internet net thru a router, you cannot connect to the router, you don't get name resolution...?

I cannot get to the internet via my router 192.168.1.254


please post the output of "netstat -rn"

http://ubuntuforums.org/attachment.php?attachmentid=121611&stc=1&d=1247996080


Can you ping your gateway 192.168.1.254?

No


sudo dhclient

http://ubuntuforums.org/attachment.php?attachmentid=121612&stc=1&d=1247996082

[Kraut~salat]

well there we have it. Your default rouet is incorrect.

See the output of netstat -rn. The line with "Destination 0.0.0.0" also says "Gateway 0.0.0.0". That is incorrect, it should be 192.168.1.254 there.

Type:
route del default
route add default gw 192.168.1.254
netstat -rn

that should fix it. Also make sure you have
nameserver 192.168.1.254
in your /etc/resolv.conf


edit: just saw that your DHCP doesn't work at all (No DHCPOFFERS received). That will reset your IP adress to some random number in the 169.xxxxx region. You have to set it back to the 192.168.1.0 net manually.

[higgins]

route del default
route add default gw 192.168.1.254
netstat -rn

After doing that I can now ping the gateway however I still cannot get on the internet. Attached is the output of netstat -rn below:

http://ubuntuforums.org/attachment.php?attachmentid=121617&stc=1&d=1248000072

[Kraut~salat]

What does "cannot connect" mean? You cannot resolve a server name via DNS or your requests are not forwarded by the router? Does
ping 209.85.129.104
work?

What happens if you try
ping www.google.com
? Can it resolve the host name?
Is your router working? I get the impression it is not, since your DHCP doesn't work at all. Then probably your routers DNS service doesn't work as well and it probably doesn't forward inet requests.

Also post the output of
cat /etc/resolv.conf

[higgins]

What does "cannot connect" mean?

My browser does not display any pages


You cannot resolve a server name via DNS or your requests are not forwarded by the router?

Names and IP addresses are not resolving


Does ping 209.85.129.104 work?

No it says:

PING 209.85.129.104 (209.85.129.104) 56(84) bytes of data.
From 192.168.1.5 icmp_seq=2 Destination Host Unreachable
From 192.168.1.5 icmp_seq=3 Destination Host Unreachable


What happens if you try ping www.google.com ? Can it resolve the host name?

No, it says:

ping: unkown host www.google.com


Is your router working? I get the impression it is not, since your DHCP doesn't work at all. Then probably your routers DNS service doesn't work as well and it probably doesn't forward inet requests.


Yes router is working, I have a windows box that was assigned an IP via DHCP from it.


Also post the output of cat /etc/resolv.conf

#Generated by NetworkManager
nameserver 192.168.1.254

[Kraut~salat]

the "destination host unreachable" message tells me that your router is not forwarding your traffic (assuming your default route is still set to the router's ip adress). This could be, because you set your own ip manually. Maybe the router only accepts requests from hosts it assigned ips via DHCP. I can't help you anymore at this point. If your default route is correct I would look at the router for the problem. I wonder why it doesn't assign an ip to your PC via DHCP. Once you fixed that you probably fixed everything

[higgins]

I checked my router and Mac address filtering was enabled. This prevented it from working...

I thought I only had this on for wifi but it seems its enabled for ethernet too.

I added the mac addresses of my two NICs and its working