Force browser (Chrome OR FireFox) to use specific network interface

Question

I need to be able to view pages of my website from outside our network. I need to be able to use separate nameservers as well. Ive found the easiest way is to just launch an SSH tunnel, then I can use the OSX networksetup command to duplicate an existing interface and implement the proxy settings and different nameservers..

sudo networksetup -duplicatenetworkservice "Wi-Fi" "Wi-Fi-External" # Create a new WiFi interface
sudo networksetup -setsocksfirewallproxy Wi-Fi-Public localhost 8123
sudo networksetup -setsocksfirewallproxystate Wi-Fi-Public on
sudo networksetup -setdnsservers Wi-Fi-Public 8.8.8.8 8.8.4.4

And this works fine for now, but when im done testing and need to go back to using my internal network, I have to disable Wi-Fi-External or change the network service order.

Is there a way to launch any browser (either Chrome or FF, or whatever will work), to use a specific network interface? And everything else default to the normal one?

I found this thread which has a similar problem, but theres no accepted answer. The most popular one says to set a default route, but that wouldn't be specific to a specified application/browser.

Any help would be appreciated. Thanks!

Answer 1

This is what ForceBindIP does. However, some have problems getting it to work (I believe the browsers do multi-process and ForceBindIP doesn't at the moment, or soemthing?) So, test to be sure it's working right. https://r1ch.net/projects/forcebindip