Thanks to all who responded.
Turned out that reverse lookups were failing because the in-addr.arpa
record for that subnet did not include the primary nameserver with an NS
record, but pointed to a secondary NS record which was failing to do
reverse address lookups for that subnet.
Thanks for all the suggestions.
This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:12:52 CDT