My organization has internet service through the same ISP, but with two separate physical circuits. We are doing BGP with them and having them route our Class B such that one portion is routed through circuit 1 and another is routed through circuit 2.
For example, 220.127.116.11/19 is announced to the ISP via circuit #1 and 18.104.22.168/19 is announced via circuit #2. They take care of announcing the entire 22.214.171.124/16 to the rest of the internet.
My question - can this same thing be done if circuit #2 was with a second ISP? Even though it is a Class B (of which we own the entire block), can two providers announce separate /19 subnets of it?
you could definetely do that with two differnet ISPs, and control the traffic based on what you want.
As for /19, it shouldnt be a problem because some ISPs not all reuires minimum /24, Of course thier is always exceptional cases.