Red Hat Enterprise Linux 6 is different from Red hat Enterprise Linux 5.X
1. Open /etc/gdm/custom.conf and edit the security and xdmcp section like the followings:
[security]
DisallowTCP=false
[xdmcp]
Enable=true ;其实只添加这行也可以
Port=177
2. Add UDP port 177 to the Allow list on firewall.
防火墙关闭的就不用修改
/etc/sysconfig/ipchains文件中加入以下语句：
-A input -p udp -s 0/0 -d 0/0 177 -j accept
3. As an admin, do 'init 3' and then, 'init 5'
修改/etc/inittab，将
id:3:initdefault:
修改为：
id:5:initdefault:
If you have enabled XDMCP and open UDP 177 on the server, make sure gdm is running. Use 'ps -aef | grep dm' and it should give you the display manager that is running on the server.
