Gateway disappears, can't connect to internet
 

okay, i've got a dell inspiron 8600 with an intel 2200bg wireless card built in, and it seems to have installed correctly. I'm using Fedora Core 3, and i get a response when i ping any machines on the local network, and i get a decent signal in KWiFiManager.

When i type in route, i get one entry, as follows:
192.168.0.0 * 255.255.255.0 U 0 0 0 eth1

The default gateway is set correctly in my network configuration, but the default route is not being added to my routing table. If I add it manually, it seems to disappear after a moment.

If I run:
route add default gw 192.168.0.1; ping (insert outside address)
i receive the first three or so packets correctly (ie they got out and back), but then I start receiving "ping: sendmsg: Network is unreachable".

If I run:
route add default gw 192.168.0.1; route
I get two lines,
192.168.0.0 * 255.255.255.0 U 0 0 0 eth1
default speedtouch.lan 0.0.0.0 UG 0 0 0 eth1
as expected.

However, if I then run route again, my default gw entry has disappeared.

Just to re-iterate, I have correctly set the default gateway under Applications... System Settings... Network. It is set for the correct interface (eth1) and all other interfaces (just eth0) are disabled.

Why does my default route keep disappearing?

Any Ideas anyone? please :) ?

Come on guys.. i asked this question in 04.. i still haven't solved it
 

I'm still stuck without wireless on my linux partition. I get online for about 5seconds, and then for some reason the gateway route just vanishes in a matter of seconds...

So, when i add it and run route, it's there, but a few seconds later, i run route, and it's gone (as well as my internet connection). Any ideas?

I am having the exact same problem. The default route on eth1 is disappearing. I have a IBM thinkpad T42 with ipw2200bg built in. I tried updating the dhclient in /sbin/dhclient to the latest release but still no luck. Not sure what is going on.

OK. I figured out my problem. I had the Network Manager running and for some reason it was overwriting the routing information. Once I shut down the network manager, I have wireless........finally!!!!

dialing ppp can couse this
 

I had the same problem as you describe.
When I restarted network, the default gateway was in routing table but seconds after it disappeared.
Even If I added default gateway by hand it was gone few seconds later.
I realized that pppoe tries to make a connection which deletes the default gateway on failure.
Fixing pppoe fixed default gateway too.