Increasing Ubuntu linux screen resolution window size in VirtualBox

Initially Ubuntu linux installed in virtualbox only showed two screen resolution options with the maximum being 800×600. To increase this I had to do the following

1. From top of virtual window, clicked on devices then select “Install Guest Additions”, it should have popped up a window indicating new virtual files are available to install but for some reason nothing happened.

1. So I downloaded and installed the necessary required files by running the command

sudo apt-get install build-essential linux-headers-generic

2. Created the /etc/X11/xorg.conf file with the following content.

Running Both Windows and Ubuntu Linux 10.04 LTS without dual boot.

You can run both Windows and Ubuntu Linux from windows by using virtualbox which is similar to vmware. Infact, you can run any linux distro from within windows using virtualbox. The example here uses Ubuntu 10.04 desktop LTS.

Step1:Download and install VirtualBox

The installation and uninstallation is like any windows program. You should preferably have at least 1GB memory to use virtualbox

Step2: Download Ubuntu image (.iso) file and save to hard disk

I find that it 32 bit iso image works best even if you have a 64 bit windows host.

Cisco VPN Client error ‘Connection Terminated Locally by the Client’

If cisco vpn client errors with the message connection terminated locally by the client in windows vista or windows 7 try this:

1. In the Start menu, right-click on the Command Prompt, and select “Run as Administrator.”
2. Enter the following line:

   reg add HKLM\System\CurrentControlSet\Services\Tcpip\Parameters /v ArpRetryCount /t REG_DWORD /d 0 /f

How to check duplicate IP adderss in your subnet.

Create and execute a script as shown below to check for duplicate IP in example: 172.16.1.0/24 subnet.

for i in $(seq 1 254);
do
echo “arping -q -D -I eth0 -c 2 172.16.1.${i}”; [ $? -ne 0 ] && echo “172.16.1.${i} duplicate”;
done