DOS – Boot Files

In order to get a USB disk to boot into a DOS prompt you will need to have the required boot files. These files can be found here.

ESXi – How to enable SSH

To enable SSH you will need to do the following, In the ESXi console press ALT+F1 Type unsupported(as you type you will not see anything on the screen) Enter the root password Edit the file /etc/inetd.conf and find the line which has #ssh and remove the #. Then Type /sbin/ restart

ESXi White Box – HP DL140

White Box is a term used to describe a hardware spec/platform that has been used outside of the Vendors recommendations. In order to run VMware ESXi on a platform outside of the Vendors HCL (Hardware Compatibility List) I used various Whitebox resources to run ESXi on the below, HP Proliant DL140 G1 (2x 3Ghz Xeons … Read more

Windows – Installing exe shows MSI dialog Box

Issue When trying to install an .exe which contained an msi, you are just prompted with the MSI help dialog box.  Resolution Goto ‘Start / Run‘ and type CMD Once in the CLI type ‘echo %temp%‘ to find your default temp folders. Remove as much as you can from your temp folder. Try to run … Read more

Windows – What are Ports needed for Active Directory ?

In order to add a machine to the Active Directory (Domain) or to allow you machine to speak with a Domain Controller you will need to open the following ports, LDAP         – TCP+UDP/389DNS          – UDP/53SMB          – UDP/138SMB          – TCP/445 Kerberos   – UDP/88

Common Sed Examples

Below are some of the common uses and commands for sed that I have come across over the years, Find and Replace sed -i ‘s|arp|/sbin/arp|g’ /etc/init.d/proxyarp Find and Delete sed -e ‘/^$/d’ file.txt Remove Multiple words This will remove word, word1, or word2 from the file input.txt sed ‘s/word\|word1\|word2//g’ input.txt Change the first instance on … Read more

Windows – I can`t connect to my Wireless Network

Issue  I can see my wireless network but when i try to connect it says that it maybe out of range and that it cannot connect. But I can connect using a 3rd Party program such as Netgear Smart Wizard etc ?? Whats going on ?? Solution Check to see if you have set up … Read more

XP – Cannot login to Domain

This can be down to many many reasons. One reason can be due to “trust relationship between this workstation and the primary domain failed”. You can resolve this by adding the machine back to a workgroup then adding it back into the domain. Further information can be found here

PowerPoint – Error “Cannot create a hyperlink to ^0”

Issue When I try to play a slideshow I get the error, Cannot create a hyperlink to ^0 Solution This is down to the hlink.dll file being corrupt. The “Official” fix for this is to copy over a new one to system32 and register. You can register this by going to run and executing the … Read more

Linux – Setting up VNC Server

Below is a short guide to set up a VNC server within Linux. INSTALL Install the package by running the following commands, Ubuntu/Debian – apt-get install vnc4server xinetd Fedora/Redhat – yum install vnc-server PASSWORD Set the password for vnc by running the command vncpasswd START VNC Start the vnc server by running the command vncserver.You … Read more

UNIX – Add an interface Redhat / Fedora

To add a interface you need to do the following,   1. Confirm what the mac address is by running ifconfig -a  2. Then edit the relevant script , which can be found at /etc/sysconfig/network-scripts/ifcfg-eth0. The script can be ifcfg-eth1, ifcfg-eth2 etc etc.  3. And it should look something like this (for a static IP), … Read more

Linux – cp: omitting directory error

When trying to use the cp command you receive the error message, cp: omitting directory This can be overcome by using the -r option, cp -r [source file] [destination file]

BASH – Adding coloured text

This will simply print your text in red.  echo -e ‘\E[31mThis prints in red.’; tput sgr0 If you need any further information or want to know how to add bold, underlining, or background colours to your text click here. 

Windows – How to add a route

Go to the Command Prompt via `Start / Run / CMD`. And use the following syntax, Add a route route -p add [Destination] MASK [Mask] [Gateway] Remove a route route -p delete [Destination] MASK [Mask] [Gateway] Example This would add a route to network via your gateway address of route -p ADD MASK … Read more

Linux – Unable to send email using Postfix

Below outlines the issue and resoultion when trying to send email using Postfix. Issue When trying to send an email on my linux platform I get the following error message in my mail.log ?? The IP you’re using to send mail is not authorized 550-5.7.1 to send email directly to our servers.      Please use the … Read more

UNIX – TCP/IP Stack Modifications

Solaris Prevent DoS /usr/sbin/ndd -set /dev/tcp tcp_conn_req_max_q 1024/usr/sbin/ndd -set /dev/tcp tcp_conn_req_max_q0 2048/usr/sbin/ndd -set /dev/tcp tcp_time_wait_interval 60000/usr/sbin/ndd -set /dev/ip ip_respond_to_echo_broadcast 0/usr/sbin/ndd -set /dev/ip ip_forward_directed_broadcasts 0 Disable redirects /usr/sbin/ndd -set /dev/ip ip_ignore_redirect 1/usr/sbin/ndd -set /dev/ip ip_send_redirects 0 Disable Source routing /usr/sbin/ndd -set /dev/ip ip_forward_src_routed 0 Linux Kernal 2.2 Prevent DoS /sbin/sysctl -w net.ipv4.tcp_max_syn_backlog=1280/sbin/sysctl -w net.ipv4.vs.timeout_timewait=60/sbin/sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1 … Read more

UNIX – IP Forwarding

IP forwarding is the process of forwarding packets from one network to another. Below shows the necessary steps to enable/disable IP forwarding. Solaris Enable IP Forwarding ndd -set /dev/ip ip_forwarding 1 Disable IP forwarding ndd -set /dev/ip ip_forwarding 0 Check the status ndd -get /dev/ip ip_forwarding Linux Kernel If the output is 1 IP forwarding … Read more

UNIX – Process State Codes

O – On processor — the process is executing on the CPU in either user or system mode. R – Runnable — the process is on a run queue and is running or runnable. S – Sleeping — the process is waiting for a I/O event to complete. Z – zombie — process, terminated but … Read more

The Ultimate Linux Command Reference Guide

 The Ultimate Linux Command Reference Guide Note: This was produced with Ubuntu. Tip: Theres quite a few in this list so I suggest that if your looking for something spefic use the search function (ctrl+F)…. a2p               – Awk to Perl translatoraconnect          – ALSA sequencer connection manageracpi              – Shows battery status informationacpi_listen       – ACPI event listeneraddr2line         … Read more

Solaris – Configuring an Interface

In this example we will configure interface qfe1 with the an IP of and set the speed to 100 full duplex. Bring up the Interface To bring up and plumb the interface, we first need to type the following, (change the IP to yours) ifconfig qfe1 plumbifconfig qfe1 netmask up Update … Read more

UNIX – Mounting a partition in Linux

In order to mount a hard drive we need to add an entry to the file /etc/fstab. This entry will allow us to not lose our drive mounting after a system reboot. /dev/sdb1       /mypartition       ext3    defaults        0       0 Then to action the changes run the following command, root@server:/# mount -a Finally check that the drive … Read more

Linux – VNC Blank Screen

Edit the/root/.vnc/xstartup file so it reads, xrdb $HOME/.Xresources xsetroot -solid grey x-terminal-emulator -geometry 80×24+10+10 -ls -title “$VNCDESKTOP Desktop” & gnome-session & After doing this kill the vnc processes and restart. Note : You may need to change the last line if you are using KDE.

Linux – Setting a Default Gateway

First of all run the command to enter the default gateway, route add default gw Then to make sure it survives a reboot, edit the file ‘/etc/sysconfig/network‘ and add the line below. Of course changing the IP address to your default gateway – GATEWAY=

Windows – I`ve forgotten / lost my Windows Password

If you have forgotten or lost your Windows Admin password have no fear, just follow the steps below. 1. Log into a limited account and in command prompt run the following. This will copy CMD.exe in place of the login screen, so when XP reboots it will present you with a command prompt window with … Read more

UNIX – Recursive Grep

Below will grep for all files containing the word ssh at the beginning of the line. The BOL symol is ^.  grep -r ^ssh /etc

UNIX – Syslog – Quick Guide

Here’s a quick overview of Syslog, there’s much more to it and you can find tons more information in the links at the bottom of the page. Syslog stands for the System Log protocol. It allows for the sending and receiving of event messages and alerts across an IP network. Operating on either UDP or … Read more

Ubuntu – Cannot install via apt-get

Issue I cannot install via apt-get as I get the message, E: Package ssh has no installation candidate When running apt-get install [package name] you get, root@ubuntu:~$ sudo apt-get install sshReading package lists… DoneBuilding dependency treeReading state information… DonePackage ssh is not available, but is referred to by another package.This may mean that the package … Read more

Debian – Add a Default Gateway

Below should the configuration steps for adding a default gateway to Debian. root@host:~$ route add default gw [ip address]  Note : Remember to add it (to survive a reboot) to your ‘/etc/network/interfaces’.Add the following entry to required interface within the interface file – gateway [ip address] Below is an example : auto eth0iface eth0 inet … Read more

Windows – Speedup Shutdown Times

As you know theres nothing more annoying then a PC that takes ages to shutdown. These registry settings wil increase the speed in which windows stops processes and services once the user has initiated a shutdown. Download Shutdown Registry Fix Here (Virus Scanned) Windows Registry Editor Version 5.00 [HKEY_CURRENT_USER\Control Panel\Desktop]“WaitToKillAppTimeout”=”1000”“HungAppTimeout”=”1000” [HKEY_USERS\.DEFAULT\Control Panel\Desktop]“HungAppTimeout”=”1000”“WaitToKillAppTimeout”=”1000” [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control]“WaitToKillServiceTimeout”=”1000” [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]“ClearPageFileAtShutdown”=”1”

Windows – MSI runas fix

As default (SP1 & SP2) you could not do a run as on an MSI file, which in a windows admin role, is somewhat of a pain……. Below is the reg entry to fix this annoying feature, just copy the below (including the windows line) into notepad, save as a .reg file then once saved, … Read more

Solaris – How to add a route

To add the route, use the following syntax, /usr/sbin/route add host [destination ip] [via ip] Then add this as well to your routes script (so it survives a reboot) in the /etc/rc?.d, i normally just do a find for the routes file in /etc. find /etc -name *routes*   If there isnt one then you will … Read more

What have you been doing on my machine ?

A few reg keys which you may find useful to find out what someone has been doing on your machine. reg query HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRreg query “hkcu\software\microsoft\internet explorer\typedurls”reg query hkcu\software\realvnc\vncviewer4\mru Get to this reg key via the regedit GUI (via run / regedit) HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\RecentDocs\.doc 

Enable Active Mode FTP in Internet Explorer

By default Internet Explorer is configured to run in passive mode ftp when using it as an ftp client (over http).To change the Internet Explorer FTP client mode to Active, do the following, Start Internet Explorer. Click Internet Options on the Tools menu. Click the Advanced tab. Uncheck the box “Enable Folder View for FTP … Read more

Want to learn more about Operating Systems and Databases?

Here is our hand-picked selection of the best courses you can find online:
Linux Mastery course
Linux Administration Bootcamp
Learn Linux in 5 Days
Windows Server 2019 Administration course
Windows 10 Troubleshooting course
Complete VMware Administration course
VMware vSphere 7 – Install, Configure, Manage
Complete SQL Bootcamp
and our recommended certification practice exams:
AlphaPrep Practice Tests - Free Trial