Ubuntu, 3Proxy, two network interfaces, two providers. How?

Question

ubuntu

I rummaged through a bunch of linux setup articles with two or more channels (providers) but did not find the right one.
We have an ubuntu16 host with two network cards. Networks 192.168.1.0 and 192.168.2.0. 3Proxy latest stable. ip_forward is enabled.
First interface ip 192.168.1.1/24. gw 192.168.1.254 (Provider 1 "static white")
Second interface ip 192.168.2.1/24. gw 192.168.2.254 (Provider 2 "dynamic" nat)
Socks and more work fine so
socks -n -p15001 -i192.168.1.1 -e192.168.1.1
socks -n -p15101 -i192.168.2.1 - e192.168.2.1
I need
socks -n -p15001 -i192.168.1.1 -e192.168.2.1 like this.
But that doesn't work.
How to win? You can poke at the material or describe the setting for this case. Or suggest your own plan.
PS Questions why do you need this and why you do not need to ask. The answer is obvious. Thanks in advance.

Answer 1

you can search for routing + packet mapping
in my answers, but there is not a solution, but links to options