VTEP Pool Size (How many addresses do i really need?)

[mike-simpson]

So..... Turning up a couple new fabrics and I need to know how to figure how many IPs I [REALLY] need for the VTEP pool. I know that Cisco suggests 10.0.0.0/16 but do I really need to do that? Is a /22 enough? I am going to be using IPs that are non-overlapping. We are using the 10.0.0.0/16 network for sites and other private network needs within our environment. I am on a really large network so I need to carve out a subset of the 10 space to use.

[stcorry]

Hello! What is suggested, is to use RFC 6598 IP space, as many organizations do not already use this (100.64.0.0/10) and it should not be routable. This can be carved up nicely into the recommended /16 subnets for the VTEP space for multiple fabric. With that said, in all likelihood, if the fabric doesn't exceed more than a few leaf switches, a smaller subnet can be used, but it should still be fairly large as the way the fabric allocates IPs is not 100% efficient. A /22 would probably be okay for a small lab fabric (no guarantees there), but for production you probably wouldn't want to go below an /18, but that should not be a problem if you go with the 100.64.0.0/10 space.