Debian server: VPN and NIC matters
 

I have a Debian server which must be placed behind a secured corporate Intranet.
Only way in is via a VPN.
The app deployed on this server needs to "call home" to a remote server via the Internet to check for latest updates, patches, data, licensing info, etc.

There are 2 NICs on this server:
- First one is configured for the Intranet LAN and the app server is listening on this NIC's IP because the app is being served to Intranet users.
- Second NIC is configured to a gateway which has Internet access, and this NIC's interface is disabled by default and is only turned on on demand.

1) How can I bridge the 2 interfaces such that the app is able to access the Internet via the 2nd NIC interface?

2) When I connect to the server through VPN from outside, I can ssh into the server but the moment I do "ifup eth2" I lose the ssh connection. Is there any way (e.g. some config settings maybe?) to allow me to still maintain the ssh connection after the 2nd NIC is up?

If there is an Internet connection on NIC through the LAN swhy can't it update through that connection? Aside from that is the second NIC on the Same subnet or what? Because I cannot think of anything other than routing tables being messed up or being on the same subnet that would cause NIC one networking to blow out when you bring NIC 2 up.