Apologies if this is the incorrect forum, but I figured networking was the closest match to the problem. I have a number of Linux clients that perform user authentication/mapping against AD (PDC is running 2k3 Std). Everything has been working absolutely fine for quite some time with this setup. However this week I was made aware that there is a number of CLOSE_WAIT entries building up, an example of which is: [user@server1 ~]# netstat | grep CLOSE_WAIT tcp 1 0 server1.company.com:44958 server2.company.com:ldap CLOSE_WAIT For the most part this isn't causing any problems, however it came to light because one of our in-house applications would not run as a certain socket was in use by one of these connections. The PDC does not have any corresponding entries when running netstat for the used ports. I've performed a number of searches to try and ascertain what the exact problem is and how to resolve it but have come up empty. The affected machines are running a mixture of Ubuntu and Slackware. Any insight would be greatly appreciated as I'm at a dead end with it right now.