GDM locks up when XDMCP clients try to connect
I have 3 linux servers running Redhat 9.0 on my network. They all use GDM as their display manager. Users use the Cygwin X server to connect to each of the machines using XDMCP. The machines have been configured and working properly for approximately 6 weeks. Suddenly last week, when everyone came in in the morning, none of the remote connections worked to any of the machines. What appears to be happening is that GDM locks up when anyone tries to connect. You're even unable to log in at the console graphically (using GDM). Another symptom seems to be that ssh logins are slow. It takes approximately 10 seconds to return a password prompt after the initial connection. Once the user is logged in, the session seems to work normally. I've tried running netstat and lsof but there doesn't seem to be anything unusual. Rebooting the machines doesn't help. I've tried removing one of them from the network and connecting with a single pc over a direct connection and the problem still existed. Has anyone ever seen anything like this before? If so, please help.