How many nameservers?

[shulkae]

How may NS entries typically is allowed per zone? Is there a bind
limit or does it cause any side effects if the
slaves are geographically distributed ?

We would like to setup one zone for my new group who have offices all
over the world ? We are planning
to use BIND 9 over FreeBSD. There may be few SUN/Solaris hosts as
well.

We would like to start with around 16 Slaves per master per zone. Is
this too much? My tests did not reveal any side effect fortunately.

Anyone with experience of setting up DNS slaves all around the globe
please advise..

Warm regards
Shal