How to make static ip for ubuntu server 3g router?

Question

ubuntu

Actually a question for connoisseurs:
There is the Internet, which can sometimes disappear - the usual lan.
I bought a 3G modem, I want to make a backup Internet.
1) How to make sure that when the main one is turned off, the traffic switches to another one and vice versa automatically?
2) Is it possible to make crutches a static ip 3G modem through free services like comexe.cn/noip.com?

Answer 1

1) Yes, it is possible.
2) If you need an external static or dynamic IP address, buy it from your carrier.
An external (whether dynamic or static) IP address costs money for telecom operators, but personally I don’t see any point in “feeding snickering parasites” due to the presence of at least 3 solutions that can “bypass” restrictions for using DDNS services in cases where the telecom operator issues "gray" IP addresses.