I am putting together a new gateway machine that controls all of the traffic in and out of one of our offices. We we have a machine with CentOS Linux release 7.2.1511 (Core) with 3.10.0-327.10.1.el7.x86_64
kernel which is now equipped with three nic cards. We decided to change our internet providers, but unfortunately Comcast would not allow us to drop there service without some penalties so management decided to keep the line and not put up a fight. Of the three nic cards, one card serves the local network inside the office, and the other two will connect to the two different internet lines.
This has resulted in providing us with two outbound internet lines that we can use. I decided to do some experimenting to see if I could use iptables or other venues to use both outside internet addresses to augment our bandwidth.
Can anyone refer me to any tutorial or give me suggestions as to how to route outbound SSH traffic that is generated from one of the machines inside the network through only one of the specified nic cards on the gateway. I would like to see if I can utilize this extra band width by splitting SSH traffic and html traffic. Essentially, I would like to force outbound SSH traffic on only one of the outside nic cards.