Xmanager Forum

XDMCP connection failed

Last post: Wednesday, March 6, 2002 9:28 PM by Support, 1 reply

Wednesday, March 6, 2002 8:07 AM - Wing

XDMCP connection failed

My question is related article No. 98. Gordon Jones said he tweeked the host to fixed XDMCP connection failed error. I have the same problem and I tried his suggestion and worked. I want to what does the hosts file have to do with XDMCP connection? The client computers on my network are using DHCP configuration. I don't want to update the hosts file veryday. Is there way to work around it?

Many thanks
Wednesday, March 6, 2002 9:28 PM - Support

Re: XDMCP connection failed

The problem might happen due to an incorrect DNS configuration. The DNS has two configuration files, forward and reverse lookup table. The two files have "name-to-ip" and "ip-to-name" entries for each IP address allocated by DHCP. A mismatch in the two-way mapping is the reason why XDMCP connection fails.

You can verify it using "nslookup" utility in Linux. Let's assume that your PC's name is "pcname" and IP address is "":

# nslookup pcname
# nslookup

The result of the two commands above should be matched exactly. If a mismatch is found, you should change the DNS entry that has an incorrect mapping. For RedHat Linux, you can edit the following two files:


For any other Unix servers, please contact your system administrator.

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