USG FLEX H SNAT to a pool of Internet addresses with two or more providers

Aleksey_Kh

Situation that providers provide subnets when connecting and there are several providers where traffic is balanced (backed up) is typical.

In most (in all of my cases) large companies this scenario is used. Otherwise, if 500 clients come from one IP, there will be a guaranteed captcha and a ban in many services like YouTube

On fortigate\microtik this is done elementarily, by specifying the addresses to which you need to click, I am attaching a screenshot from fortik

Example:

Provider 1 gives me a subnet/29 of addresses 1.1.1.1-4 (gigabit link)

Provider 2 gives a subnet/29 of addresses 2.2.2.1-4 (gigabit link)

Provider 3 gives one IP 3.3.3.1 (gigabit link)

Provider 4 (starlink) gives one IP 4.4.4.1 and will be used only if provider 1,2,3 fails

I want VLAN21 clients to be evenly balanced through providers 1,2,3, from addresses 1.1.1.2-4, 2.2.2.2-4, 3.3.3.3 and in case of failure of providers 1,2,3, the traffic goes through starlink