How do I access a server from a specific IP?

Question

I have a two systems on a private network 192.168.0.0/16.

SysA has an IP of 192.168.0.30 SysB has two subinterfaces in linux, ETH0:0 with IPs of 192.168.200.213 and ETH0:1 192.168.90.20.

If I'm on SysB how can I get it to access SysA through the 192.168.90.20 IP instead of the 192.168.200.213 IP?

Answer 1

You'd have to look into Source Routing for Linux. An example can be found here in the Linux Advanced Routing & Traffic Control HOWTO:
http://lartc.org/howto/lartc.rpdb.html#LARTC.RPDB.SIMPLE

Actually, even simpler you can do something like this:

ip route add to 192.168.0.30 src 192.168.90.20 dev eth0 via 192.168.90.1

Assuming that the gateway is 192.168.90.1, change it accordingly if needed!