Which of the Following Default Port Numbers Need to Be

question 74

Multiple Choice

Which of the following default port numbers need to be open on a firewall for a mail server to successfully send and receive mail? (Choose three.)

• A) 22
• B) 25
• C) 53
• D) 80
• E) 110
• F) 143
• G) 161

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Definitions:

Output Coil

A component in PLC programming that represents a physical output device and is controlled by turning it on or off within the program.

TOF

Stands for "Timer Off-Delay," a function in PLC programming where a timer starts counting when the input turns off.

Timer Off-delay

A timing function in control systems that keeps the output active for a predetermined time after the input signal has been turned off.

Output Coil

In programmable logic controllers (PLCs), an output coil represents a device or actuator to be controlled by the PLC's program.