I work on a server (BSD), which for security reasons is set up to allow connections only from a particular IP address. This is problematic because I have a dynamically assigned IP address on my Mac laptop, and that's not something that I can change. For now, my workaround is to tunnel through a colleague's desktop computer (Ubuntu), which does have the correct IP address. He is the sysadmin for the server, but is a very inexperienced sysadmin with a lot on his plate, so finding other server-side solutions may not happen quickly. He has told me that he can set multiple IP addresses for his own machine, which is what I would like to do on my Mac. The one time I tried to set my IP address manually with
ifconfig, it screwed up my VPN connection, which I need to maintain.
So my question is, how can I manually set an IP address for a terminal session on my Mac in such a way that it doesn't interfere with other network activity, which may require a different IP address?