Category: SysAdmin

Unix Archive Tools

The cpio(1) name is derived from CoPy In and Out. Cpio was standardized in POSIX.1-1988, but it was omitted from POSIX.1-2001 because of its file size and other limitations. The use of cpio by the RPM Package Manager make cpio an important archiving tool.

Using free public DNS servers

The DNS is an essential part of the internet, it translates hostnames such as into IP addresses DNS also plays an important role for routing emails.

Bash Tip - Beware of spaces

Everyone knows that filenames and variables can contain spaces, but when it comes to writing a shell script most of the shell developers seem eager to forget that fact and write scripts that do not safely handle filenames containing spaces. I can't count the numbers of time I saw people …

Bash Tip - The importance of testing that variables are defined.

When writing code it's important to make sure all the variables are defined. Using an undefined variable can lead to all sorts of problems. Your program may fail randomly or run commands with unexpected results. Almost all languages raise an error when the program tries to access a variable that …

Using OpenBSD to build a secure access point

At home I have two networks, one for my family and me and one for my guests. Once you are on the family network you can access our backup server, our music and video server, our printers, etc. The guest network can only access to the internet.

Build you own stratum-1 NTP server for less than $100

You can build a highly accurate Stratum-1 NTP Server for less than $100 using an old Wyse WinTerm, a GPS and a few electronic components.

Using SSH with an SSH bastion

One of the tasks of system administrators is to secure the machines inside of their network. To do so you usually configure access lists on your router to prevent access from the outside. If all the ports are blocked the system administrators won't be able to connect to the port …

Page 1 / 2