• How To Create OpenVPN Server for Secure Remote Corporate Access in Linux Debian/Mint/Ubuntu with client public key authentication


    Why choose OpenVPN instead of a firewall appliance? OpenVPN can be a reliable and easy replacement for traditional hardware or just be an additional tool that your company uses so that the firewall can focus on its job rather than acting as a VPNappliance at the same time. When comparing OpenVPN with traditional firewal........
  • how to use ifplugd in Linux to execute a command or script when a NIC cable is unplugged or plugged in


    It is fairly simple to use once you know how to use it. However, the tricky thing is that by default it doesn't seem to be active or listen on any interface on manually specified. How To Install ifplugd First we install ifplugd sudo apt install ifplugd Let's enable it on our desired device(s) vi /etc/default/ifplugd set this line as so:........
  • Cisco IP Phone How To Reset To Factory Settings Instructions CP 9971, 8800, 8900, 8845, 8851, 8841, 8831, 7961, 7960, 7945, 7942, 7941, 7940.


    This would be crucial especially if the phone is hardened, not being able to reset or change settings could prevent a phone registering in a new environment or even when migrating from office to office. This applies even if you are trying to migrate the phone to another platform such as Asterisk/FreePBX etc... This guide applies to nearly all of the Cisco IP phones that you would use in CME or CUCM from several years ago including models: 9900, 9971, 8800, 8900, 8845, 8851, 8841........
  • imagemagick convert to chop off top of image


    This is useful if you have a bunch of images/scans where the same area at the top needs to be chopped. Sometimes the -trim option (such as the case of white space on top)is wrong and ends up cropping the image and losing some text. ImageMagick's convert is very useful but tricky to find some things out as I find it to be less than intuitive sometimes. Chopping off the bottom convert -crop -0-400 image.jpg image.pdf........
  • How To Install Seamonkey Web Browser on Debian Ubuntu Linux Mint


    You can download the latest Sea Monkey releases here and 64-bit issues are a thing of the past now: It's a little tricky if you are running a 64-bit OS which most people will be. The weird thing is that the Seamonkey website for Linux seems to only provide a 32-bit download. seamonkey-2.49.2.tar.bz2 Seamonkey is still provided as a tar.bz2 which you need to extract and run manually. First........
  • bash scripting for loop set number of iterations


    A handy trick in bash that can be adapted to many useful tasks: for i in {1..99}; do echo $i done 1 2.. 97 98 99 100 Another tricky is if you need a 0 in front of the first letters: for i in {1..12}; do if [ $i -lt 10 ]; then i=0"$i" fi echo $i........
  • Postfix how to secure outgoing authenticated e-mails for privacy and hide the IP address, mailer and other things


    The most common solution is to use the /etc/postfix/header_checks but this is a big problem. Why is header_checks a problem? Because it does it to all mail whether incoming or outgoing and whether authenticated or not. We of course want as much header information for incoming as we can get for many reasons but many organizations want to secure and make their mail clients as secure as possible. I adapted this solution to the client's custom config, they are configur........
  • cp ignore symlink and copy the actual file


    This can be very tricky, say you are doing development on a file that is symlinked. Doing a "cp dev.file dev.file-bk" won't do what you expect, it just links back to the same file so you haven't copied or backed anything up. You need the "-H" switch to copy the actual file that is referenced by the symlink: cp -Hdev.file dev.file-bk........
  • pcnet32: eth0: transmit timed out, status 97fb, resetting - NIC card problem solution


    I've encountered this problem before and I believe it may affect other drivers (I could test but I don't have time). This was happening on my custom Linux system with the pcnet32 driver. pcnet32: eth0: transmit timed out, status 97fb, resetting (and some other kernel module tracing in dmesg) Basically it means the card is connected (it shows connected in full duplex etc.. and recognized if the cable is disconnected too) but no packets can be sent or received........
  • mencoder Linux CLI video editing how to encode video file into xvid and split by time into multiple parts


    Mencoder is great, you can throw anything at it, including video files from your camera and have it encode into xvid or almost any other format. In my case I took 640x480 video from my Canon and reduced the size by 1/3 with the options below (there are many other options that you can read about in the manual but I like to keep it simple). Mencoder Encode mencoder -ovc xvid -oac mp3lame -xvidencopts fixed_quant=4 -o ........
  • SATA Power cable for 1U Server Solutions - Rosewill 8" SATA Power Cable Model RC-8"-PW-4P-2SA


    NewEgg is one of the few companies that stocks this great right angle 1U SATA power cable. I've purchased some no-name ones and they face the wrong way (towards the bottom of the chassis) which makes it worse/impossible than standard SATA connectors. The price is high but if you're building a 1U server and want SATA disks and don't have much space (eg. the 1U Supermicro cases) then these are simply a must and........
  • Tyan S2735-8M Maximum Hard Drive Limit/Not Working/Doesn't work with 1TB 1000GB hard drives


    Inever saved any of the logs, but basically no matter what OS (Linux)I used, I could not get my 1000GB hard drive to work (Seagate SATA). The BIOS recognizes the drive and fdisk -l shows the hard drive as it should. The tricky thing is that different OS's will give you different results, but don't be fooled. You can't use these larger drives for long. Iwas getting all kinds of seek/IOerrors and also messages that the port could not be read.........
  • MySQL Restoring And Dumping/Backing UP MySQL Data/Tables/Databases


    Backing MySQL Databases Backing Up/Dumping All Mysql Databases To A Single File mysqldump --all-databases -u admin -p > allmysqldatabases.sql The "-all-databases" clause is pretty obvious isn't it? It means that it will backup all databases. The "-u admin" means login using the user "admin", if you h........
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