Hello everybody,
I am running a debian 2.6.10 on my server.

Today I rebooted it after more than a year. But I was not able to connect to internet using it.

I used ifdown eth0 and then ifup eth0, then I got ip address and ifconfig proved that.

But when I try to nmap myself using 130.65.42.1, it says host seems to be down.

I checked /etc/network/interface and changed it to dhcp, so that I could get IP from DHCP and I got IP from it, but my internet doesn't work still.

Even static IP didn't help me.

I am not even sure if my ethernet card modules are loaded, because I don't know what I should look for when issuing lsmode.

Any idea what's wrong with it?

by the way, my ethernet card is 3Com and I am not sure if its module is loaded

If you have a firewall running, you probably cannot use nmap unless you give it the -P0 switch. (that's P and a zero). Have you tried to ping your gateway? Or try pinging your DNS servers? I'd say your module is loaded if you are getting an IP address.

yes I have tried -P0 option to nmap myself, gateway and 3 different DNS inside /etc/resolve.conf

I guess there is a firewall installed on this machine, so that it doesn't let me connect to internet. I have not configured this system, so I have no idea about it.

I talked to my DNS server admin about this problem. Once they pinged my computer, everything started working normally. I really didn't understand what happened.