Ubuntu 8.x, 9.1, 10.04, 10.10, 11.10, 12.04 XDMCP Configuration

Owned by Support
May 23, 2018

1. Display manager configuration

  • GDM (Ubuntu 10.10 and previous releases)
    If you are using Ubuntu 11.10 or later releases, skip to the 'Configure LightDM' section.

    Open the following GDM configruation file

    Ubuntu 8.x: /etc/gdm/gdm.conf-custom or /etc/X11/gdm/gdm.conf
    Ubuntu 9.1, 10.04, 10.10: /etc/gdm/custom.conf

    and set Enable to 1 in the [xdmcp] section and DisallowTCP to false in the [security] section as following.

    [xdmcp]
Enable=1

[security]
DisallowTCP=false


    *Ubuntu 10.10 had a bug in its GDM (v 2.30.5) that only allowed IPv6 connections which caused Xmanager to fail connecting to the host. This bus was fixed in GDM version 2.32.0.


  • Configure LightDM (Ubuntu 11.10 and 12.04)
    If you are using Ubuntu 10.10 or previous releases, you can skip this part.

    Create the /etc/lightdm/lightdm.conf file and save the following lines:

    [XDMCPServer]
enabled=true


    *In order to use Xmanager with LightDM, you must upgrade Xmanager to the latest release. Use the Help > Check for Updates menu to upgrade.


2. Firewall (TCP/UDP Ports) Configuration

  • Open UDP port 177 from the PC to the remote host direction.
  • Open incoming TCP ports 6000~6010 from the remote host to your PC.


3. Restart display manager and start Xmanager

  • To restart gdm (gdm users only)

    # init 3; init 5 (Ubuntu 8.x)

# /etc/init.d/gdm restart (Ubuntu 9.1, 10.04, 10.10)

  • To restart LightDM

    # service lightdm restart