How to configure Redhat EL6 use XDMCP (Xmanager)

我使用的是Win7，防火墙"入站规则"中阻止了Xmanager服务，一开始找不出原因，走了些弯路

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.

If it it not running, please make sure the display manager such as gdm or kdm is installed on the machine. Red Hat 6 does not install display manager by default. 

1. 编辑/etc/inittab, 修改默认启动级别为5, 重启系统

id:5:initdefault:

2. 编辑/etc/gdm/custom.conf, 启用xdmcp

vi /etc/gdm/custom.conf

# GDM configuration storage

[daemon]

[security]

[xdmcp]
Enable=1

[greeter]

[chooser]

[debug]

3.在防火墙上开启允许177端口的访问

4.重启系统

5.widows中启动xmanager broswer，file->new->New Session Wizard…（我使用的是xmanager3.0）
6.选择 XDMCP (For running an X Windows Enviroment)->Next
7.Method 选择XDM Indirect host输入要管理的机器地址，Port Number输入177->Next
8.X Server Profile 使用Auto Select,选中 Allocate displaynumber automatically->Next
9.Name 可以随便输入一个自己方便记忆的名字，或者保持默认->Finish
10.双击新建的Session启动连接，等待一会会出现连接选择，选择我们的要登录的系统点连接就可以看到我们熟悉的 6的登录界面了

Disable SELinux on RedHat RHEL 6

Edit /etc/sysconfig/selinux and add a line saying
    SELINUX=disabled
and then reboot.