Several 4g modems in OS, how?

Question

linux

Comrades, hello!
There is a task, you need to proxy the Internet through several 4g modems.
There is an incoming channel, requests come through it, they should fall on the proxy (I think a squid) and he, in turn,
each modem tries to become the main one when connected, i. we make ourselves the default gateway, but this is solved by interrupting routes.
But when the signal is lost, I noticed that the modem can reboot itself, and as a result, the routes will fly off again.
How to prevent the modem from sending commands that change routes?
Maybe there is some other solution?
PS I don't need to aggregate, I need to get several different addresses and hook them into the proxy.

Answer 1

namespaces

Answer 2

Read about ip rule, ip route.
Raise modems not through NM, but through some kind of wvdial.