Category: Windows XP

Port opened? Telnet is your friend

Do you want to know if the problem you are having is a network \ firewall issue?

You can simply use Telnet to check if the port you are trying to connect to is open or not.

You can test any port using this simple method, not just connections open to telnet.

First off you need to install Telnet Client on your machine.

To do so, open a command prompt window. Click Start, type cmd in the Start Search box, and then press ENTER.

pkgmgr /iu:"TelnetClient"

Next step close the current command prompt and reopen it again, this is so the path to Telnet which you’ve just installed will work.

Now type the connection & port to test

telnet <server> <port>

Example

telnet google.co.uk 80

If it goes to a blank screen or a screen with funny characters then this means that port is open.

If you get :

Connecting To google.co.uk..Could not open connection to the host, on port 80:Connect failed

Then you’ll need to get onto your network team to open some firewall rules for the required port access or iptables if on unix servers.

Forensic disk recovery

If someone gave you a Sandisk Cruzer 8GB micro USB stick*, which had their entire life of work stored on it. This stick couldn’t be directory listed under Windows 7 only Windows XP.. nothing could be copied off nor copied on to it.

What would you do ?

Well here’s what I did to recover the files.

first of all I tried all the normal windows based solutions:

Chkdsk
Recovery software GetDataBack – (Which has served me well in the past)

No joy! Nothing! Nada! – USB just disconnects when you try anything.

So I turn to Unix for the answer, the USB stick could be mounted and read, it just crashed out when trying to copy the files/directories from the device, saving about 10% of the data.. I’m assuming its a hardware failure of the device.

This is when I turn to open source forensic software – Ubuntu Rescue Remix

Here’s how I used it :

I created a bootable image of the Ubuntu Rescue Disk ‘to a different USB stick’, following the instructions at Pendrivelinux.com

Booted that, then used the following commands :

Create ‘hdd1’ directory in the ‘mnt’ folder
sudo mkdir /mnt/hdd1

Mount your machines hard drive to the folder ‘/mnt/hhd1’
sudo mount /dev/sda1 /mnt/hdd1

Check the ‘mount’ command to see what the USB device your trying to recover is called, in my case its mounted as ‘/dev/sdc1’
sudo mount

Use that information to constuct the following command; ddrescue-retry to read upto 3 times-USB device-name of image to write-name of log to write
sudo ddrescue -r 3 /dev/sdc1 /mnt/hdd1/recovery-image /mnt/hdd1/recovery-log

Create a new directory on your hard drive to store all the recovered files.
sudo mkdir /mnt/hdd1/recovery

Run ‘foremost’ which is some forensic software created by the US Air force; foremost-image name-output directory
sudo foremost -i /mnt/hdd1/recovery-image -o /mnt/hdd1/recovery

This will extract files ‘Without filenames’ to the output directory, slight issue, but lucky to get anything back at all.

* Other USB sticks are available..