enterprise linux

I‘ve the NetworkManager service is installed and started under Linux desktop. The applet is running. The NetworkManager can display available network hardware and wireless networks. But, I’m unable to add VPN support as the Add tab is greyed out. I need to use both PPTP and Cisco vpn clients. How do I fix this problem under Debian or Ubuntu Linux?


I’ve edited /etc/ssh/sshd_config to change the port number:

Port 1255

However, I’m getting an error as follows:

sshd[26792]: error: Bind to port 1255 on failed: Permission denied

How do I change default OpenSSH port number from 22 to 1255 under RedHat Enterprise Linux server version 6 and SELinux?


I‘m trying to use semanage command to configure certain elements of SELinux policy without requiring modification to or recompilation from policy sources under RHEL 6 server. But, I’m not able to find out this command and/or package name. How do I install semanage command under RedHat Enterprise Linux?


How do I configure the Internet Protocol version 4 (IPv4) properties of a network connection with a static IP address for servers running Linux operating systems? How do I configure static IP address under Debian Linux or Redhat / RHEL / Fedora / Redhat Enterprise Linux server?


How do I check the ram size from my Redhat Linux desktop system using command line and GUI tools? How do I find out memory size on Red Hat Enterprise Linux server?


What the differences between a Linux or UNIX software update and an upgrade? How do I perform the both?


We have corporate intranet network for our web site as us.example.com, jp.example.com (asia.example.com), uk.example.com (eu.example.com). How do I replicate static content stored at /var/www/corporate_lan/ such as javascript files, css files, and images between our USA, Japan and UK web servers running under UNIX or CentOS or Redhat Enterprise Linux based Apache servers?