I get 'Xdmcp connection failed: cannot open display' and connection fails

Owned by Support
May 11, 2018
1 min read

PROBLEM DESCRIPTION

When you try to connect to an XDMCP session from Xmanager, Xmanager displays a grey background and the XDMCP connection eventually fails. The Xmanager log file shows:

Xdmcp Request Address: 192.168.1.5
Xdmcp Connection Address 0: 192.168.1.4
Xdmcp: sent a REQUEST message
Xdmcp: received an ACCEPT message
Xdmcp: sent a MANAGE message.
Xdmcp: Timed out, state 8. Retransmissions: 0
Xdmcp: sent a MANAGE message.
Xdmcp: Timed out, state 8. Retransmissions: 1
Xdmcp: sent a MANAGE message.
Xdmcp: Timed out, state 8. Retransmissions: 2
Xdmcp: sent a MANAGE message.
Xdmcp: received a FAILED message.
Xdmcp fatal error: Session failed Session 86 failed for display example.domain.com:0: Cannot open display


*This article requires remote server configuration. Administrator privilege may be required.


RESOLUTION

This problem is usually caused by one of the following reasons:


  1. Firewall settings on PC, physical firewall, gateway or router.
  2. Incorrect entry in the DNS.
  3. Improper operation of display manager such as gdm, kdm or xdm.


Depending on the reason, try the following solutions:


Firewall settings on PC, physical firewall, gateway or router

Follow the instruction on the Xmanager FAQ and configure your firewall.

How can I configure firewall settings in Windows?


Incorrect entry in the DNS

Add your PC IP address in /etc/hosts as following:

172.16.2.120 PC_NAME


Improper operation of display manager such as gdm, kdm or xdm

Restart the display manager process. You can also try restarting the remote server.