A chronological documentation test project, nothing serious, really!
This is a little HOWTO (or tutorial) about swapping/inverting two color channels. I will swap the red and the blue color channel using Adobe Photoshop CS 3 to create a more “normal” looking picture with a blue sky on my infrared photo taken with my Nikon D80 and a Hoya R72 67mm IR-filter. I will […]
This is a simple example of how you can populate a /etc/hosts file with 100 IPs and hosts from the command line # N=1; for i in $(seq -w 100); do echo “192.168.99.$N host$i”; P=$(expr $P + 1); done >> /etc/hosts The result file /etc/hosts 192.168.99.201 host001 192.168.99.201 host002 192.168.99.201 host003 192.168.99.201 host004 192.168.99.201 host005 […]
Add the following line if your SSH login takes a long time on your SSH server. File /etc/ssh/sshd_config: UseDNS no Restart the SSH daemon to activate this change.
Multiport The Multiport extension allows you to specify multiple ports and ranges and makes it possible to create complex rules in one line. Here’s an example of how you can allow SSH, Web, IMAP and X terminal traffic iptables -A INPUT -p tcp -m multiport –dports 22,80,143,6000:6003 -j ACCEPT The alternative to using this rule […]
ufw (Uncomplicated Firewall) is a new and easy firewall/iptables tool introduced in Ubuntu 8.04 LTS (Hardy Heron). ufw is a front-end for iptables-restore, with its rules saved in /etc/ufw/before.rules, /etc/ufw/after.rules and /var/lib/ufw/user.rules. Administrators can customize before.rules and after.rules as desired using the standard iptables-restore syntax. Rules are evaluated as follows: before.rules first, user.rules next, and […]