> Use different GUA ranges for internal and external. It's easy enough to > get an additional prefix. > > > As others have mentioned, things like management interfaces on access > switches, printers, and IP phones would be good candidates to hide with > ULA. > > Or non-advertised, filtered GUA. Works just as well either way. > > Owen >
If one is obtaining "another" prefix for local addressing, I see no benefit. I am assuming that anyone that is using ULA is using it for things that don't communicate off the site such as management interfaces of things, etc. This won't be a subnet you are connecting by VPN to another organization, usually, but even if you do the chances of collision is pretty low if you select your nets properly. But for the most absolutely paranoid site, I can see some appeal in using ULA in conjunction with DNS64/NAT64 and see them giving the devices internet access via v4. Not that I agree with the notion, mind you, just that I can see someone looking at that as an appealing solution for some things. Even if someone managed to get through the NAT device via v4, they would have nothing to talk to on the other side as the other side is all v6.
