How to do it...

1. Browse to the directory where ike-scan is installed.
2. Install autoconf by running the following command:

apt-get install autoconf

1. Run autoreconf --install to generate a .configure file.
2. Run ./configure.
3. Run make to build the project.
4. Run make check to verify the building stage.
5. Run make install to install ike-scan.
6. To scan a host for an Aggressive mode handshake, use the following command:

   ike-scan x.x.x.x –M -A

The following screenshot shows the output of the preceding command:

1. Sometimes, we will see the response after providing a valid group name such as vpn:

ike-scan x.x.x.x –M –A id=vpn

1. To view the list of all available options, we can run the following command:

ike-scan -h 

The following screenshot shows the output of the preceding command: