Modify ip-tables directly in ubuntu

To modify ip-tables directly in ubuntu First save off your current config: $ sudo -s $ iptables-save > /root/working.iptables.rules $ iptables-save > /root/ At this point you can modify the file.  Once your are satisfied restore it # iptables-restore < /root/  

Configure postfix with Gmail via Webmin

Configure postfix with Gmail via Webmin This assumes the user has webmin installed and understands how to log in and use it. (Usually bring it up in a browser at https://localhost:10000 ) Make sure that postfix is installed. In Webmin this is done by going to “System”, “Software Packages” then clicking on “Package from APT” and... » read more

useful active directory scripts

Scripts to manage Active Directory Users Appending a Multi-Valued Attribute Appending a Phone Number Adding a Route to the Dial-In Properties of a User Account Adding a User to Two Security Groups Appending Address Page Information for a User Account Appending a Home Phone Number to a User Account Assigning a Published Certificate to a... » read more

Red Hat Linux cheat sheet commands examples RHEL

Useful Linux Commands (Red Hat) ( Revised 3/1/2000 Getting information man commandname display the manual page for a particular command named commandname man -S sectionnumber commandname display the manual page under a specific section numbered sectionnumber for the command named commandname. Sometimes the same command will exist in more than one section. man alone will... » read more

shutdown ubuntu linux

How do I use shutdown command? The shutdown command can be used to turn off or reboot a computer. Type the command as follows to shutdown server / computer immediately: $ sudo shutdown -h now OR $ sudo shutdown -h 0 How do I shutdown compute at specific time? To shutdown computer at 6:45pm, enter:... » read more

x11vnc was unable to open the X DISPLAY

Having trouble getting x11vnc working? Here’s the error: [email protected]:/etc/X11/gdm# x11vnc -forever -usepw -httpdir /usr/share/vnc-java/ -httpport 5800 -auth /var/gdm/:0.Xauth 06/10/2010 16:28:21 *************************************** 06/10/2010 16:28:21 *** XOpenDisplay failed (:0) *** x11vnc was unable to open the X DISPLAY: ":0", it cannot continue. *** There may be "Xlib:" error messages above with details about the failure. You must... » read more

freebsd find

How to find files, programs, etc using freebsd The locate command is good for finding files and directories. Enter something similar to: locate someprogram | more If that doesn’t work, perhaps try the whereis or find commands: whereis someprogram | more find / -name "someprogram*" For variations on these commands, you can type: man locate... » read more

vmware unix

A great place to find vmware virtual machines for freebsd, ubuntu, cent os, red hat linux (RHEL), Linux Mint, etc is over at bagside’s virtual appliance repository here’s what they offer: Virtual Appliance Repository. This site is dedicated to virtual appliances that we build for you to use FREE of charge (except for Windows 7... » read more