1.修改/etc/gdm/custom.conf文件
[daemon]
[security]
DisallowTCP=false
AllowRemoteRoot=true
[xdmcp]
Enable=true
[greeter]
[chooser]
[debug]
2.修改/etc/sysconfig/iptables文件
# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -m state --state NEW -m udp -p udp --dport 177 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 177 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 6000:6010 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
3.重启防火墙
[root@localhost init.d]# ./iptables restart
windows 下使用xmanager访问CentOS6.5
原文：http://www.cnblogs.com/zy-zhaoyu/p/4113294.html