Well I set up a ppp connection for my USB modem. I even got an IP address but when I try to do a ping I get network unreachable.
I think it could be because the same laptop also sometimes get connected to office LAN for which the default GW is set to 192.168.1.1. That could be the reason why the packets do not get routed when using PPP connection.
What do I do so that when I use my USB modem ( dialled using wvdial ) the default gw is set automatically to whatever is appropriate and when I am on a LAN using ethernet the default GW is 192.168.1.1
I think my problem is this http://tldp.org/HOWTO/PPP-HOWTO/x452.html