You would need to setup an in-addr.arpa record on the nameserver that is authoritative for those IP addresses.
As an example, our internal network has IPs in the range 10.1.x.x (subnet 255.255.0.0). Basically the IP addresses are reversed, so for 10.1.x.x we have a zone "1.10.IN-ADDR.ARPA", then we have a zone file that looks something like:
@ IN SOA localhost. root.localhost. (
2000101001 ; serial
3600 ; refresh
900 ; retry
1209600 ; expire
43200 ; default_ttl
@ IN NS dc1.largenets.com.
; Routers and necessary network (10.1.0.x)
1.0 IN PTR mercury.dc1.largenets.com.
2.0 IN PTR uranus.dc1.largenets.com.
253.0 IN PTR neptune.dc1.largenets.com.
254.0 IN PTR pluto.dc1.largenets.com.
; Network Servers in DC1 (10.1.1.x)
1.1 IN PTR earth.dc1.largenets.com.
2.1 IN PTR andromeda.dc1.largenets.com.
3.1 IN PTR milkyway.dc1.largenets.com.
Then, you'll need to put something in your named.conf like:
This of course assumes you have access to the DNS servers that are authoritative for your IPs. If you don't, you'll have to get the datacentre to do it.
I hope that helps a bit. If you need any parts clarified, just ask!