I am trying to connect to the internet with a cable modem. I have configured linux to connect using dhcp. It seems to work fine, since when I run ifconfig I get a valid IP address, and when I run some kind of network monitor I notice there is a little bit of data being passed thru my network card. However, I cannot connect to anything on the internet. I get messages that say :host not found" or something like that. I know this sounds vague, but any help would be appreciated.

Dan

Set up /etc/resolv.conf with your domain and nameservers identified. It should look something like this

[i]/etc/resolv.conf:

search home.com #domain to search on
nameserver xxx.xxx.xxx.xxx #primary dns
nameserver xxx.xxx.xxx.xxx #secondary dns

I would also run tcpdump -i (interface hooked to cable modem)(eth0?) -l |tee tcpdump.out

This will dump all tcp traffic to your screen and you can see if your talking or not, and it will also make a file with this info, run this for about 5 minutes if you are still having problems and post some of the output here for troubleshooting. If it was a DNS problem and everything works fine, running tcpdump is still a good learning utility, you should run it to see what tcp traffic looks like.

I checked the /etc/resolv.conf file and it was configured correctly.

I tried to run tcpdump and putting the output to a file, but I couldn't get that to work, so I ran it and captured the screen after it had run for about 15 seconds. the screen capture is at: http://www.cse.psu.edu/~ferullo/pic.jpg

Dan

I know it's a pain, but the more detail you can give the easier it is for people to try and help.

Now, can you post what EXACTLY you were trying to do when you got the "host not found" message? Also, can you ping your gateway and DNS servers? That is a good test to start with.

I will try to be more explicit:

when i boot linux the eht0 interface starts up fine. i get an ip address using dchp, and this is how the dns servers where established (ie, i never input any dns/gateway/ip information)

I am using RH7.1

When I try to go to a website on the internet (ie yahoo) I get a message that says something like "host not found' or "the host www.yahoo.com could not be found" or something like that...i forget the exact wording.

I cannot ping either of the dns servers that are in the etc/resolv.conf file. both of them return the error message "Network unreachable"

I ran tcpdump, ifconfig, and the RedHat Network Monitor and tried pinging myself (using the ip address ifconfig determines). While doing this I saved a screen shot and uploaded it at: http://www.cse.psu.edu/~ferullo/ note that the lo interface begins to show activity right at the time i started to ping myself (but the eth0 interface always had activity..before i started running tcpdump) Also, the eth0 interface generally shows activity of about 120B, but at times it shows activity up to 10KB, and sometimes shows red activity (i assume this is me sending info to the server). This seems to happen at logical times, like if i try to open a website. However, I wasn't able to capture any of this odd behavior of the eth0 interface in a screen shot.

Let me know if any additional information would be helpful, and thanks in advance for your help.

Dan

I have a similar problem but all I have to do is open my network config program in KDE save it, close it and my internet connection works. I have no idea why this happens or how to get it to work properly but I know It's a temporary fix(for me at least) I've checked my resolv.conf and hosts files an there seems to be nothing amiss. Any Ideas??