No, the same Internet Protocol.
I believe he meant different IP addresses
No, that can't be, he would have said "IP addresses".
and I highly recommend doing so.
If you do so, then you can move services around and name things independent of the actual host that they happen to be on at the moment without having to renumber or rename.
The DNS is already a layer of indirection so in most cases this makes things harder first (having to remember which address is on which host) so they may be easier later (not touching the DNS when services go to a new box). In my opinion, this isn't a good tradeoff most of the time. Only if you want/need addresses to be a particular way (like short for DNS servers) that's helpful.
Far from it. Running services on separate IP addresses is extremely important to enable services to move (to a different box) independently. It has little to do with wanting addresses to be a particular way, and much more to do with *other* places (e.g. firewalls) where IP addresses are used and not names.
I was reluctant to do stateless autoconfig for servers at first but it's really rock solid, as long as you're reasonably sure no rogue router advertisements will show up on the subnet in question there's no reason to avoid it.
Shudder. Steinar Haug, Nethelp consulting, sthaug@nethelp.no