What is the maximum value for the IP ID field?

What is the maximum value for the IP ID field?

• A. 65535
• B. 4294967295
• C. 255
• D. 1024

Answer: (A)

The IP Identification field is 16 bits wide, so it can hold values from 0 to 2^16 − 1. That maximum is 65,535. The other numbers correspond to different bit widths (255 is for 8-bit fields, 1024 isn’t the max for a 16-bit field, and 4,294,967,295 is the max for 32 bits), but for a 16-bit field the highest possible value is 65,535.

The IP Identification field is 16 bits wide, so it can hold values from 0 to 2^16 − 1. That maximum is 65,535. The other numbers correspond to different bit widths (255 is for 8-bit fields, 1024 isn’t the max for a 16-bit field, and 4,294,967,295 is the max for 32 bits), but for a 16-bit field the highest possible value is 65,535.