Your network is a mixed environment of Windows, Linux, and UNIX, computers. The routers are primarily Cisco and the network uses a T-1 to connect to the Internet. You are experimenting with setting up a mail server in a production environment for internal use only. You do not want this mail server to receive any requests from anywhere but the internal network. Therefore you have decided to block incoming SMTP traffic at the Firewall. Which port will you block at the Firewall?

In order to properly manage the network traffic in your organization, you need a complete understanding
of protocols and networking models. In regards to the 7-layer OSI model, what is the function of the Session Layer?