I have an Ubuntu 16.04 server which has access to to two gateways to the internet. (192.168.15.1 & 192.168.15.250)
15.1 has significant bandwidth but does not allow any port forwarding from the wider world. 15.250 will allow port forwarding.
I want to use dynamic DNS to ssh into this machine so naturally I need to use 15.250 for this purpose, but i want applications to by default go through the high-bandwidth connection.
How can I get the external IP of 15.250 whilst using 15.1 for the majority of traffic?