Telnet test simulation in Unix and Solaris

Simulating telnet test in Linux ans Solaris is very easy. NC tool used to simulate the telnet test,We do telnet test to validate the connectivity between two machines.Telnet test gives us information mainly host and port are accessible from another machine. In order to validate this service should be running on specific port in other machine and in case this not running how can we simulate the port accessibility?

If the service is already running on specific port we can do the telnet test as like below.

telnet 128.25.65.12 8090

Now if the service is not running how to simulate telnet behavior?. This can be achieved by using 'NC' utility in linux/solaris. To simulate telnet first we need login destination machine and we need to start the system in listening mode as like below.

nc -l 8090

Once destination machine is started in listening mode, We can hit telnet test as mentioned abouve.