Private domain?

[Jim Dossey]

Please forgive me if this has already been answered.  If this is covered
somewhere else, just point me in the right direction.  I've searched the
archives and haven't come up with anything conclusive.

I have a private network.  It is connected to the Internet using a
router running NAT.  I want to setup an internal DNS server that will do
external lookups, and it also needs to be primary DNS for a fake domain
for the internal machines.  I don't want to use an internal domain that
will conflict with a real domain somewhere on the Internet.  This is
similar to the private IP addresses of RFC 1918.  I suppose we could
register a private domain to ensure that we will never conflict, but I
am hoping that there is a domain reserved for this use.

Thanks,
Jim Dossey