Which Default Ports Should Be Opened on a Firewall for SSH and Telnet?

Which of the following default ports should be opened on a firewall to allow for SSH and Telnet? (Choose two.)

A.

21

B.

22

C.

23

D.

25

E.

123

F.

443

BC.

The correct answers are B) 22 and C) 23.

Secure Shell (SSH) and Telnet are both terminal emulation protocols used to access and manage network devices remotely. They both use different default ports, which need to be opened on a firewall to allow incoming traffic to these protocols.

Here are the default port numbers for SSH and Telnet:

• SSH: TCP port 22
• Telnet: TCP port 23

Firewalls are network security devices that monitor and control incoming and outgoing network traffic. To allow incoming traffic to SSH and Telnet, the firewall needs to have rules that permit traffic on TCP ports 22 and 23, respectively.

Option A) 21 is the default port number for FTP (File Transfer Protocol), which is used for transferring files over the internet. It is not related to SSH or Telnet.

Option D) 25 is the default port number for SMTP (Simple Mail Transfer Protocol), which is used for sending email messages between servers. It is not related to SSH or Telnet.

Option E) 123 is the default port number for NTP (Network Time Protocol), which is used for synchronizing the clocks of network devices. It is not related to SSH or Telnet.

Option F) 443 is the default port number for HTTPS (HTTP over SSL/TLS), which is used for secure web browsing. It is not related to SSH or Telnet.