Connect to 2 different networks at same time?

[OSXconvert]

I have a 2008 imac which has built in wireless. Is there some way to use the wireless to connect to internet while using the ethernet jack to connect to a different LAN so it can connect to a fileserver?

Or if that isn't possible, can I join my LAN network to the one which provides internet access without having to change all my LAN addresses? My goal is to maintain a private gigabit LAN while getting internet from somebody else in my office.

Thanks for your help. And please excuse my ignorance because I know very little about networking.

 

[Brian33]

I doubt I know any more than you, but since the wireless and ethernet are separate network interfaces, I'm pretty sure they can connect to two different networks. At least I know my iMac can be connected via Ethernet to my Time Capsule and simultaneously connected via wireless to the (same) Time Capsule. (I have an '08 iMac also.)

I used to know a Terminal command to show the interface devices and their status but I've forgotten it.

Have you tried it?

 

[ActionableMango]

Yes. The two networks should be different subnets.

 

[OSXconvert]

Yes. The two networks should be different subnets.

Thanks for that clarification. I'll give it a try.