Reverse DNS on non-network .0 addresses

[Chris Tata]

Hi,

I'm trying to get reverse DNS working on two .0 addresses that aren't designated as network IP's.  I am currently allocated a /22 network: xxx.xxx.40.0 - xxx.xxx.43.0  I am unable to propigate reverse DNS for xxx.xxx.41.0 and xxx.xxx.42.0 even though they aren't used as a network IP's.  I do use forward DNS on those IP's and interface aliasing with the .0's works fine.  Am I incorrect in assuming that the 41.0 and 42.0 addresses are *not* network identifiers?  My subnet mask for all of the IP's in the range is 255.255.252.0 with the network address being 40.0 and the broadcast address being 43.0

Any suggestions?

Thanks 

- chris