The iftop command listens to network traffic on a named network interface, or on the first interface it can find which looks like an external interface if none is specified, and displays a table of current bandwidth usage by pairs of hosts. iftop is a perfect tool for remote Linux server over ssh session.
Iptables has a special module called owner (ipt_owner), which is attempts to match various characteristics of the packet creator, for locally generated packets. It is valid in the OUTPUT and POSTROUTING chains.
PHP4 or PHP5 do not have any problem to execute php3 files. The only problem is you need to force PHP4 or PHP5 to understand .php3 file extension as a php script.
You need to use the sudo command to grant a permission to other users to shutdown your server. The sudo command allows a permitted user to execute a command as the superuser or another user, as specified in the /etc/sudoers file. Login as a root user and type the visudo command to edit the sudoers file.
Have you ever wondered why shutdown account exists on Linux server, especially under Red Hat Enterprise Linux distribution?
The answer is quite simple – shutdown account can shutdown server. Here is how you can enable the shutdown account: