forgetting something simple on network config

[Davy]

i have a gateway machine at 192.168.1.3 and all boxen on my computer use it happily. (they're all attached to a router; but the gateway box is not the router).

laptop with ubuntu 8.10 and atheros wifi. atheros driver installed and works. (just installed it this morning).

i use gnome's network manager applet to set gateway to 192.168.1.3 and dns to 123.456.789.101 and 123.456.789.111 (those aren't the real addresses, all the other boxen use them just fine). i can ping the other boxen (even the gateway) fine; but i can't get to http://www.anything. traceroute isn't installed and ping can't resolve.

so i shut down network manager and try it manually:
/etc/init.d/networking stop
ifconfig ath0 down (to shutdown wifi)
ifconfig ath0 192.168.1.4
vim /etc/resolv.conf to add 123.456.789.101 and 123.456.789.111
ifconfig ath0 up
/etc/init.d/networking start

here's where it gets weird:
route says that my gateway is Macintosh-00039 and resolv.conf have both my addresses; but i STILL can't surf.

it's exactly the same situation i was in before.

what am i forgetting/doing wrong?

[teeitup]

What's the output of /sbin/route ?

[Satanic Atheist]

This is rather complicated, but I hope I've understood it correctly. The "router" I presume is simply your Internet gateway but your "gateway" is the actual machine that routes packets to the Internet, yes?

The fact that your other machines can access the Internet is confusing the whole lot and therefore would indicate a problem with the local (i.e. non-functional) machine rather than the network.

If I'm mistaken, check your output of:

cat /proc/sys/net/ipv4/ip_forward
Which is the system's ability to forward packets across interfaces for routing purposes.

I've had a similar problem whilst 3000 miles away and I needed to evade the country's web filtering so I've run a VPN link to my home (UK - not filtered) and then set up a Squid web-proxy to connect (since my server refused to forward connections under any circumstances) and this may be a possible solution for you.

James

PS. I was only checking the lottery numbers but I was in Bahrain (where gambling is illegal) in case you were wondering what I was up to.