I'm connecting to my university intranet through their VPN service. So whenever I activate VPN, I get an extra "ppp0" interface in addition to the already existing eth0 (wired), wlan0 (wireless) and lo (localhost) interfaces. It seems that, like all the other applications, Firefox connects to the internet through ppp0 when I activate VPN. I want it to connect through any interface except ppp0. How and where can I indicate this?
I'm running Ubuntu 12.04 on my laptop so I'm looking for a Linux solution to this.
Edit: Here's the output of the command "route -n" as requested by MariusMatutiae
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 0.0.0.0 0.0.0.0 U 0 0 0 ppp0
10.200.5.51 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0
138.40.178.1 192.168.1.1 255.255.255.255 UGH 0 0 0 wlan0
138.40.178.1 192.168.1.1 255.255.255.255 UGH 0 0 0 wlan0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wlan0
192.168.1.0 0.0.0.0 255.255.255.0 U 2 0 0 wlan0
Thanks!