Category: Unix
Port forwarding using SSH
SSH port forwarding let you connect to a server using another server a relay. For example, if you host a web server in a DMZ behind your office router, you
Read MoreHow about a Raspberry PI 2 as a firewall?
A Raspberry PI 2 performs as expected exceptionally well as a firewall. The download throughput achieved was 33 Mbits/sec under the same test conditions as the previous test (see Can
Read MoreMake an Apache2 SSL server more secure
These easy steps will improve significantly the security of your Apache2 SSL server. Edit your /etc/apache2/mods-enabled/ssl.conf file and replace the SSLProtocol, SSLCipherSuite and SSLHonorCipherOrder parameters with the following values. SSLCipherSuite
Read MoreInstalling memcached to use it with php
Installing Memcached with php support in Ubuntu is a matter of a few steps: sudo apt-get install memcached php5-memcached sudo service apache2 restart You can test if memcached is active
Read MoreIssues after upgrading to Ubuntu 14.04.1
After upgrading to Ubuntu 14.04.01, I ran into two issues: One with Apache2 and one with Samba 4. Apache has been upgraded from 2.2.22 to 2.4.7. The content was no
Read MoreHow to rename a user in Linux
Simply issue this command: usermod -m -d /home/new-account-name -l new-account-name old-account-name It creates the home directory if it does not exists. It also copy the stuff of the old user
Read MoreHow to use the command line to make the internal speaker beep
Two simple steps: Install the beep utility. Executing beep on the command line will make the internal speaker beep. apt-get install beep Add pcspkr to /etc/modules to load it at
Read MoreHow to prevent SSHD to listen on an address family
It is possible to control on which address family sshd will listen to. In /etc/ssh/sshd_config, simply add AddressFamily any to listen to IPv4 and IPv6 addresses. This is the default.
Read MoreHow to assign a static IP address in Ubuntu
Setting a static IP address in Ubuntu involves editing /etc/network/interfaces. If the interface is currently using DHCP, you will find these lines in the file. auto lan iface lan inet
Read MoreHow to change the network interface name in Ubuntu 12/13
Two files need to be modified to change the name of a network interface in Ubuntu. For example, if you want to change eth0 for lan, simply change the NAME
Read MoreHow to find duplicate files on Linux?
It is pretty straight forward in Linux, install fdupes. sudo apt-get install fdupes Type the following command to display the documentation man fdupes
Read MoreAccessing a serial port from a web server
On most Linux distribution, it is impossible to access a serial port (ex. /dev/ttyS0) from a web server such as Apache or lighttpd using a cgi. Simply add the user
Read MoreScript listing all the keys on a memcache server
This script lists all the keys on a memcache server. #!/bin/bash nc localhost 11211 > /tmp/$$.1 <<EOF stats items EOF cut -d: -f2 /tmp/$$.1 | grep -v END | uniq
Read MoreRecording a terminal session under Linux
It is possible to record a terminal session under Linux with ttyrec. It also records vi, emacs, etc. sessions. Fisrt, install ttyrec sudo apt-get install ttyrec To start recording a
Read MoreHow To Setup A Protected Wireless Connection Via the Command-Line
Setting up a wireless connection via the command line may vary depending on the USB Wireless Interface you are using. These instructions also work for the Raspberry PI running Wheezy.
Read MoreMasquerading or replacing outgoing SMTP email address with Postfix
Postfix can replace an outgoing email address by another one. To do so, you must perform these steps: Add in /etc/postfix/main.cf the following line smtp_generic_maps = hash:/etc/postfix/generic_maps Add in hash:/etc/postfix/generic_maps a
Read MoreCreate an ext3 or an ext4 partition without a journal
Most of the time, having a journal for ext3 and ext4 partitions is pretty useful. Nevertheless, you can prevent creating a journal by adding the option ^has_journal. For example: mkfs
Read MoreInitializing a brand new disk with “parted”
“parted” is a replacement for “fdisk” of Linux. It can handle disks larger than 2 TB. Issue this command to launch “parted” where /dev/sdL is the disk you want to
Read MoreHow to unmount an encrypted partition?
Unmount the partition umount /mnt Unmap the partition cryptsetup luksClose securebackup
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