gethostbyaddr adding IP to hostname from some clients

[Eiolon]

I log the hostname of the computers when they do certain things in our Intranet.

 

When the hostname is logged, certain clients are getting both the hostname and the localhost IP address added.

 

For example, if the PC name is TOMS-PC, the hostname logged is TOMS-PC172.0.0.1

 

Other clients are logging just the hostname as it should be.

 

All I use to grab the hostname is:

 

$hostname = gethostbyaddr($_SERVER['REMOTE_ADDR']);

 

Any clues as to what causes this?