用Xmanager連線HP-UX時彈出如下提示資訊：
The X11 forwarding request was rejected!
to solve this problem,please turn on the X11 forwarding feather of the remote SSH server

     Show reply messages 資訊如下:
[11:51:51] Connecting to '172.31.0.131'...
[11:51:51] Connected.
[11:51:51] Version exchange initiated...
 .
 .
 .
[11:52:08] Sent X11 forwarding request...
[11:52:08] Failed.

一, 一般論壇上都是以下類似的解決辦法:

將sshd_config中 設定 X11Forwarding yes
重啟sshd服務。

但是我找遍了我5臺機器的設定, X11Forwarding 的預設值都是 yes ! 既然這樣了,我還改什麼啊? 但還是徒勞的將預設選項刪除再手動敲入, 無果:(

For XDMCP connection to HP-UX 11.X
1. XDM Configuration
# /usr/dt/bin/dtconfig -e [Enable]
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. Reboot the remote host and start Xmanager
 
以上經過測試, 對於我來說完全不適用:(

三, 在HP官方網站上查到個針對HP-UX的解決辦法:
修改檔案 /etc/rc.config.d/xfs
RUN_X_FONT_SERVER=0     <<---改成 RUN_X_FONT_SERVER=1
然後重新啟動xfs . 經過測試發現還是不行.
 

四, 沒有其他辦法了,自己對/opt/ssh/etc/sshd_config 配置檔案一個一個選項的測試, 終於發現只用改動下面的這一個選項設定就可以了:

X11UseLocalhostyes

預設情況下,該設定是被註釋(關閉)的. 此辦法,在我其他4臺機器上測試過, 完全管用. 當然改完後要重啟動sshd服務 !

sshd restart :

備註: 1. 我的客戶端與伺服器之間的Firewall沒有特別管控. 所以不存在UDP埠的問題.
         2. 不明白網上的解決辦法為什麼這麼多種,缺解決不了我的問題:( ,只能解釋為不同的機器環境需要區別對待.

--------2008.8.5----更新

為什麼X11UseLocalhost 一定要設定為yes, 最近在網路上找到了可能的原因: HP-UX 11iv2 2008版本使用的sshd好像是4.X, 有一個bug存在. 必須設定為這樣才可以被Xmanager連線使用. 我舊版本的機器是3.9版的sshd, 不存在這個問題.

OpenSSH “X11UseLocalhost” X11 Forwarding Security Issue
SECUNIA ADVISORY ID: SA31179
VERIFY ADVISORY: http://secunia.com/advisories/31179/
CRITICAL: Not critical
IMPACT: Exposure of sensitive information
WHERE: Local system
SOFTWARE: OpenSSH 4.x http://secunia.com/product/5653/ OpenSSH 5.x http://secunia.com/product/19347/
DESCRIPTION: A security issue has been reported in OpenSSH, which can be exploited by malicious, local users to disclose sensitive information.
The security issue is caused due to the sshd server setting the SO_REUSEADDR option for the listening socket used by the X11 forwarding server. This can be exploited to intercept an X11 forwarding session by binding a socket to the X11 forwarding port.
Successful exploitation requires that “X11UseLocalhost” is disabled (enabled by default) and that the underlying operating system allows the re-binding of a port without checking the effective user id or the overlapping of addresses (e.g. HP/UX).
The security issue is reported in versions prior to 5.1.
SOLUTION: Update to version 5.1 or 5.1p1.
PROVIDED AND/OR DISCOVERED BY: The vendor credits sway2004009.
ORIGINAL ADVISORY: http://www.openssh.com/txt/release-5.1