Comment 23 for bug 330833

I am using 'ignore automatically obtained routes', but my original default gateway disappears when connecting to a vpn that already not push any default gw by its configuration.

eth0: 192.168.42.0/24
tun0: vpn with 213.188.*.*
virbr0: ignore it, kvm virtual subnet

$ route -n
Destination Gateway Genmask Flags Metric Ref Use Iface
213.188.*.* 192.168.42.1 255.255.255.255 UGH 0 0 0 eth0
192.168.42.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
192.168.56.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0
0.0.0.0 0.0.0.0 0.0.0.0 U 0 0 0 tun0

should be:
$ sudo route del default
$ sudo route add default gw 192.168.42.1
$ route -n
route -n
Tabella di routing IP del kernel
Destination Gateway Genmask Flags Metric Ref Use Iface
213.188.*.* 192.168.42.1 255.255.255.255 UGH 0 0 0 eth0
192.168.42.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
192.168.56.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0
0.0.0.0 192.168.42.1 0.0.0.0 UG 0 0 0 eth0

Using openvpn with the simplest configuration by hand works.