Comment 37 for bug 330833

By default, VPNs get the default route as that is the most secure configuration of a VPN. If that is not your VPN configuration, you'll need to check the "Only use this connection for resources on its network" and then only the specific routes sent by the VPN server (or ones you enter manually) will be routed over the VPN tunnel.

If you have further problems, please re-open and include some of /var/log/messages that show the IP configuration that NM is getting from vpnc. It will look like this:

NetworkManager: <info> VPN connection 'foobar' (Connect) reply received.
NetworkManager: <info> VPN connection 'foobar' (IP Config Get) reply received.
NetworkManager: <info> VPN Gateway: 101.22.183.53
NetworkManager: <info> Tunnel Device: tun0
NetworkManager: <info> Internal IP4 Address: 10.3.227.85
NetworkManager: <info> Internal IP4 Prefix: 20
NetworkManager: <info> Internal IP4 Point-to-Point Address: 10.3.227.85
NetworkManager: <info> Maximum Segment Size (MSS): 0
NetworkManager: <info> Static Route: 172.16.0.0/16 Next Hop: 172.16.0.0
NetworkManager: <info> Static Route: 10.0.0.0/8 Next Hop: 10.0.0.0
NetworkManager: <info> Internal IP4 DNS: 10.5.26.20
NetworkManager: <info> Internal IP4 DNS: 10.5.26.21
NetworkManager: <info> DNS Domain: 'foobar.com'

that will help us determine if vpnc and NM are getting the right data.