Tag Archive: agent


IP Spoofing in Loadrunner


IP Spoofing

It is a technique used for creating Internet Protocol (IP) packets with a forged source IP address, with the purpose of hiding the identity of the sender address.

IP Spoofing in Loadrunner

This technique is used in Loadrunner Agent machines, in order to make the Application server to think requests are coming from different machines. This purposely used in the Load Balancing Application servers which runs on the IP based distribution.

Procedures to configure the IP Spoofing in Loadrunner

Step 01: Get the required number of static IPs (based on number of vusers to be executed) from the Network Administrator, which should have the same ‘Default gateway’ of the LG machine.

Step 02: Follow the IP wizard in the LG machine and do the setup by adding the required number of Static IPs.

Step 03: After finishing the configuration setup, try pinging one of the static IP. It should not get ‘Timed Out’ error.

Step 04: Now we are ready to do the execution with Controller. While creating the scenario, enable the ‘IP Spoofing’ option in the LG machine.

This should work. If any issues, comment to reach me. Thanks.


The purpose of a firewall is to increase security by blocking communications and allowing communications with only certain ports, such as 80 and 443 for HTTP and HTTPS traffic.
By default, the LoadRunner Controller uses TCP port 50500 to send data to TCP port 54345 on the Windows Load Generator.
The Load Generator sends information back via a dynamic port, through the MI Listener.
To avoid having to beg Network Administrators for more ports to be opened, on each load generator machine inside the firewall, from

Start > Programs > LoadRunner > Advanced Settings > Agent Configuration (launch_service\bin\AgentConfig.exe)

install the (Monitoring Over Firewall machine) MoFW/RoWF agent.

Check the option “Enable Firewall Agent”.  It collects performance counters and sends them to a controller over a firewall. MoFW communicates with the MI Listener through port 443, so you can’t have any web servers (like Apache WebTours, IIS, or Oracle HTTP servers) running on both the machines.
Verify whether port 443 actually allows communication by running command and substituting the ip address in:
telnet 194.194.194.194 443
This should open a telnet window.

UNIX Load Generator uses a dynamic port that cannot be fixed.
When defining a “remote” load generator from within the Controller, click “Details” for the “Load Generator Information” dialog, where you can click the “Firewall” tab and check “Enable Firewall”.
Courtesy : http://www.wilsonmar.com

Loadrunner – Agent Issue


Issue: After the scenario has been set up with certain load generators, while starting the scenario we face some errors due to Load generators.

Solution: Note the scripts for which the particular load generator has been used. Open the .prm file for the particular scripts. We can see the mismatch of parameterization name from the script to the prm file of the corresponding script. Now modify the parameter name which is correctly given during parameterization in the script.

Once it is changed and restart the scenario, it will run successfully.