Yes but you might find that the name was not resolved at the time the connection was made.
I have recently had this issue with some of my ISP's name servers returning null hostnames on reverse lookups where in fact proper names were there. This seems to be a behaviour sometimes seen in very busy name servers (I think they run BIND but I don't know what version).
I just asked them for a more reliable name server to query and I have not seen this issue since.
HTH
Chris Linfoot
http://chris-linfoot.net