Monday, 30 April 2012

Tool to Scan Ip addresses

Ip scanner  ipscan.exe , a very nice tool to know the ip addressess used in the network so that you can use free ip address in lab environment.

Sunday, 29 April 2012

Tools to generate multicast traffic.

Below tools can be used to generate multicast traffic:

1) VLC player : This tool has a wizard, which can be used to generate multicast traffic.

This is the best one and I am using it for close to 5 years.

2)  Various good tools for generating multicast traffic, with good explanation on how to use them:

3) Iperf : It is very powerful tool, and can be used in number of ways:

To generate multicast stream use command:

Client; iperf -c -b 50K -t 300 -T 5 -u 1234 -i 1 -l 136

Server : iperf -s -B -u  -i 1

4) Nortan Multicast Hammer:  It was very nice tool and we used a lot but officially they have removed it ,from their webpage.

5) Qcheck : From IxChariot, free tool to download but registration required.

Friday, 27 April 2012

Tools to generate broadcast traffic

We have following tools to generate broadcast traffic :

1) ping command :

  In Linux : ping -f -b "network-address"

  In Windows : ping "network-address"

E.g.   ping -f -b ( Linux)
         ping ( (Windows)

2) Lanevel tool : A very easy-to-use interface for generating broadcast traffic.

You can download from here:

3) Iperf :

Server :
iperf -c -i 2 -t 60 -b 10000 -u"

"iperf -s -i 2 -u"

This will work fine for windows client,but may have problem with Linux .

4) Colasoft Tools :

You can copy one broadcast packet and play it using Colasoft player.

If you know any other tool , please let me know.

Windows and Linux Tool to compare and merge files

Windows :

1) Winmerge :

2) Araxis : 30 days trial period

Linux :

1) Meld:  freeware 

2) Guiffy :
    21 days trial period.

3) Kdiff3 :
     freeware and good to use.

Thursday, 26 April 2012

DHCP option 82 how to enable in Windows and LINUX DHCP Server and DHCP Relay?

In Windows 2003 server "DHCP option 82" is not enabled by default. We need to follow below method to enable it.

In ISC-DHCP server we can add options tag in dhcpd.conf file to enable this option.

In ISC-DHCP Relay we use this command to enable this option :

dhcrelay -d -a server_ip

"-a" option add "Circuit id" to the packets passing through relay. In this "Remote id" is not enabled by default, we need to modify the code to use it. Also "link state" sub -option is not supported as of now , we need to modify the code to use it, not sure why in Release notes they say that it is supported. I did not see any proper code to support it. Also it doesn't have config file to add this option.

If you know how to do it please let me know.

Wednesday, 25 April 2012

Windows batch script to start or stop a windows service.

@echo off
net stop servicename
net start servicename

To reboot PC

shutdown /r /t 0

Stopping a service, may take time and if you want to run the file using scheduler it is good if you create two files with at least 5 min gap in between.

How to know the status of DHCP Server if it is down ?

Through  ISC-DHCP forum i came to know about two great tools which will check the status of DHCP Server and if it is down will inform admin or take appropriate action.

I have not used it myself, you can try them and let me know your comments.

Monday, 23 April 2012

How to run DHCP relay in Linux, Command to run dhcrelay in Linux .

I was working on dhcp relay in Linux and came to know following things: 
 We cannot run the command giving only one interface , either it has to be all or none. 
So it can be like 

dhcrelay –d serverip


dhcrelay –d –i eth0 -i eth1 serverip 
Basically all the interfaces, including the one on which the server is connected, 
is to be specified in the command .If we give only one interface it will 
silently discard the packet. 

Please see below bug for more information.

How to kill a process in Windows ?

For killing any running process in Linux we use "kill -9 PID" . The PID or process id we can know from "ps" command in Linux.

But for windows it is slightly different:

For windows there can be two ways to kill the process :

1) Go to task manager -> select the process name and end process tree.

this works fine when you know the process name which is running in task manager.
For some process it is difficult to know exactly the process name so for that another method can be used.

2) Use command "netstat -ano" , get PID for the port no, on which your process is running, and give command "taskkill /f /PID XXXX  to kill the process.

Wednesday, 11 April 2012

OpenSource or community projects for testing ?

It is good to join any open source projects. Once you know basics there are hundreds of projects there, find one or two and join them. It helps in many ways:

1)You know how others are testing their standards, their way of testing , new tools.

2) Its improve your communication skills, when you interact with others , you learn " to listen others", " what you say and think may not be always correct", " what you write and you meant can be given entirely different meaning by different people"

3) It improves your self confidence.

For development side or coding side there are number of projects but for manual testing, I think there is limited scope but still if you are willing to, you can find one and join one and more importantly contribute in them.

Some of good online testing platform which will help you are :

1) utest:  They have a large community of testers and one can join them depending on their skill set. As there are many people in there looking for projects , i think for newcomers it is difficult to get first project.You need to be over enthusiastic with proper skill set and you may get started on this. Try your luck.

To be true i joined them 3 months back but never got projects, may be my skill set not matching with requirements or may be i m not following them very keenly :-)

2) Bugpub: For this you should have linked in profile through which you can request to join them. Also you should report at-least one public app or website bug.

In above two you get paid if you execute projects.

Others open source projects:

1) Mozilla Firefox : They have testing session on each Friday, you can join them and participate in their beta releases.

2) Ubuntu:

3) MeGo :

4) Fusesource:

6) Testlink:

the best way to get linked is , participate in that which you use on daily basis in home or office. If you use Mozilla on daily basis first try to know more and more about it by joining its community and participating in forum. Once you are comfortable in using it ask for contribution in any form in which you are comfortable.

It is always about having patience because millions of people are out there and the person who has started it will be apprehensive first , but if you are serious and it shows in your communication in forum or community they will accept it sooner or later.

So keep trying and keep learning.

Good tool to capture Youtube Videos or any other video

Sothinkmedia has two very good tool which can record any type of video and save it. Using this you can download the video to local pc and watch it later. Also using coverter you can convert into any other format and use it for testing,

iMacro Firefox addon for WEB GUI testing

iMacro is one very good Firefox addon. Using this we can record one web page actions and play it repeatedly for number of times. To install this

Go to Mozilla Firefox ->Tools-> Addon->Get Add-ons

Search for "imacro"

it will find , install it and use it. A good tool for overnight tests.

Tuesday, 10 April 2012

Common capture filter expressions used in wireshark

In Wireshark we have two type of filters : display filters and capture filters.

Capture filters common filter strings are:

1) No Multicast traffic : "not multicast"

2) No Broadcast : "not broadcast"

3) only arp : "arp"

4) only ip : "ip"

5) port 550 : "port 550"

6) traffic to and from : "host"

7) traffic from mac address 00:00:00:11:22:33: "ether host 00:00:00:11:22:33"

8) pppoe : "ether proto 0x8863 and  ether proto 0x8864"

9) source subnet 10.0 : src net 10.0

10) dns traffic ; "port 53"

Types of Wireshark filters and common filters for wireshark

In Wireshark we have two types of filters

1) Display filter which is the main filter in Wireshark Window and can be seen below:

2) Capture filter -> which we can get in options

In options we can see the capture filter

The syntax for each type of filter is different and one filter string may not work for another.

In Capture filter, before starting the capture the filter string is defined and is used only to capture those packets which are matching with the filter.

In Display filter the filter string only apply the filter and show the results, but it will capture all type of packets.

For common types of filter expression, i have made separate posts please go through them.

Which type of filter we should use ?

Well, i have seen many people using only display filters.There could be different reasons like people are not aware of capture filters or as it capture only specific packets the filter should be proper.

My say : Use capture filter if you know which traffic you want to analyze as it saves time and is not cluttered. 

Common Wireshark display filters used for testing.

Wireshark is one of the great tool to analyse traffic. If you want to understand about any protocol you should use Wireshark often and see into details of each packet.

Some of the common used display filters  with Wireshark are :

1)  arp traffic use filter as  "arp"

2)  ftp traffic use filter as "ftp"

3)  For DHCP traffic use "bootp"

4) For traffic whose src is : "ip.src=="

5) For traffic whose destination is : "ip.dst=="

6) For those packets whose ip length is more than 200 bytes : " ip.len>200"

7) Not to capture netbios traffic :"!netbios"

8) Vlan traffic : "vlan"

9) no tcp : "!tcp"

10) Arp and icmp only : "arp || icmp"

11) ip only :"ip"

12) Only dns :  "dns"

13) For traffic to and from :  "ip.addr=="

14) Telnet traffic: " tcp.port== 23"

15) Rip : "rip"

16) PPPoE related : "pppoes" "pppoe" "ppoed"

17) Snmp : "snmp"

18) SIP : "sip" 

Monday, 9 April 2012

How to share a common Excel file and update at the same time?

We use Excel sheet a lot and the problem we faced is everybody updating the sheet at the same time. The cells defined are different though.

Generally we will ask the other person to close it so that i can update my commets. I found that it has one feature which allows multiple user to update the sheet at the same time.

Go to Tools-> Share Workbook , select "Allow changes by more than one user at the same time."

Using this all users can update the sheet at the same time. The cells should be different. If same cell is modified by two persons, the last person will get notification and he/she can see what is entered by other person and act accordingly.

This saved our time :-) .

I think Excel has many good features but we dont use them as we dont know them.

Keep learning, Keep sharing.

How to enable status bar in Notepad ?

To enable status bar in notepad the wordwrap has to be disabled and vice versa.

If you want both to be enabled everytime you need to go to registry setting and edit following key.

  • Click on Start > Run > type regedit
  • Go to:HKEY_CURRENT_USER > Software > Microsoft > Notepad.
  • Double click the StatusBar and set its value to 1.
  • Confirm with OK.
  • Close the Registry Editor and launch Notepad.
Now the status bar will be grayed out, but it will be selected and you can use both the functionality. If you reboot the machine you may probably need to set it again. 

Wednesday, 4 April 2012

How to open wireshark captured packet in Colasoft packet builder or packet player ?

Colasoft  has two very useful tool for testing. Colasoft packet player and Colasoft packet builder. Using these tools you can modify the packets and send it to your network for testing.

Also if some packets you have captured using Wireshark, you can save that packet in ".pkt " format and open in Colasoft player tool to send it continuously overnight.

If you use any other format other than ".pkt" the Colasoft tool wont recognize it and you cannot open it.

You can download Wireshark and Colasoft tools from below location. Both are free and are must have tools on testing PCs