Hello,
I have problem with internet connection on Archlinux 2007.8. I am connect to the internet by ethernet card. I set up ip addres by ifconfig and gateway by route but it doesn't work. When I check the routing table I see there two gateway. The one that I set up and then second. I check rc.conf, conf for route but there is no record fo the second route. I tried to delete it by route -del ip but it always said: SIOCDELRT: No such process...

Does anybody have idea abou it?????

Prehaps you should try "route del default" to delete default gateway and set the one you want instead with something like "route add default gw 192.168.0.1".
Then if you want to connect to, say, 10.0.0.0/8 thru gateway 192.168.0.2 just type "route add -net 10.0.0.0 netmask 255.0.0.0 gw 192.168.0.2", shouldn't be much of a problem.

Yes I've tried this several times. But I think taht my problem is different. When I start PC there are two records in route table - first route(10.83.3.0) which I don't want to use.. I don't now where this route was set up.... and the second route(default 10.83.3.1). I del the first(10.83.3.0) but I cannot still reach internet....... I have Gentoo Linux on the second harddisk and there internet is working. I've checked config and they look same.....

What output do you get from executing "route"? Does this match what you see in gentoo when it works? What output do you get if you execute "arp"? Are you able to ping the gateway? Are you able to ping other hosts on the network? Are packets being sent and received from the interface (use tcpdump or snort)?

10.83.3.0 * 255.255.255.0 U 0 0 0 eth0
default 10.83.3.1 255.255.255.0 UG 0 0 0 eth0

I have the second line same as in Gentoo.

Address HW Type HW Address IFace
10.83.3.1 (incomplete) eth0

No -- Destination host unreacheble
No, same as gw

Okay, let's sort it out:
You have an NIC with IP like 10.83.3.X
From there you want to reach 10.83.3.1, and thru that the rest of the world.

First thing, naturally, to reach 10.83.3.1 you MUST have a route which includes that IP (10.83.3.1) - the route to gateway or it'll say "Destination host unreachable", that's why you have "10.83.3.0 * 255.255.255.0 U 0 0 0 eth0" route. Notice the absence of "G" flag next to "U" - its not the route thru gateway, it's just a route telling that your system can reach 10.83.3.* from eth0 interface (10.83.3.X), if you delete that of course you won't be able to reach anything.

The fact that you see 10.83.3.1 in arp means that the gateway is reachable via ethernet, so, if you have 10.83.3.0/255.255.255.0 route and 10.83.3.1 as a default gateway your system should be able to reach gw and networks behind it, and the problem is either in gw or there's no problem at all.

Check if eth0 is the same NIC as eth0 in gentoo (since you have two of them), udev can call it any name it likes / you specify so prehaps your router denies you access because your network adapter have wrong MAC address.
Another (quite common) possibility is that you're testing connection by pinging (for example) google.com and don't see any output just because you haven't specified any DNS (/etc/resolv.conf) or the ones you've specified doesn't work. Try direct IPs or check if ping is able to resolve host IP at all.