Which statement is FALSE with respect to listening ports?
- Port 443, when set to default, is encrypted.
- Ports can be numbered 1 to 65535.
- The port number does not always identify the service.
- They are closed.
Ports can be open, closed, or filtered. When they are open, they are said to be listening. When closed, they are not listening. While ports do have default port numbers, it is possible to run a service on a non-default port number.
Software ports can be numbered from 1 to 65535. The first 1024 or so are called well-known. Some of these well-known port numbers as their defaults are:
– TCP 20 and 21: File transfer Protocol (FTP)
– TCP 22: Secure Shell (SSH)
– TCP 23: Telnet
– TCP 25: Simple mail Transfer Protocols (SMTP)
– TCP and UDP 53: Domain Name System (DNS)
– UDP 69: Trivial File Transfer Protocol (TFTP)
– TCP 79: Finger
– TCP 80: Hypertext Transfer Protocol (HTTP)
– TCP 110: Post Office Protocol v3 (POP3)
– TCP 119: Network News Protocol (NNTP)
– UDP 161 and 162: Simple Network Management Protocol (SNMP)
– UDP 443: Secure Sockets Layer over HTTP (HTTPS)
Port 443 is SSL over HTTP, which is encrypted.