Re: Service providers that NAT their whole network?

[Jeff Kell <jeff-kell () utc edu>]

While not "big" by any sense of the word, we NAT [almost] all of our
internal network.  It wasn't initially a matter of choice, but rather of
necessity.  We had a sprinklings of small netblocks in the old legacy C
swamp, mostly in the old SURAnet/BBN allocation, and after the Genuity
takeover they yanked our routes on short notice (actually, our upstream
didn't notify us until the last minute).  We had to NAT into a new
temporary allocation from an upstream, and later renumbered into a
portable block for multihoming.

There are still some old Genuity addresses in use inside (renumbering is
easier said than done) but we're slowly cleaning them up.  NAT seemed to
be the best option at the time, especially since we had no portable
allocation.

We used to overload, but talk about overhead...

Jeff