How many possible sequence number combinations are there in TCP/IP protocol?

The correct answer is C. 4 billion. TCP uses a 32-bit sequence number field in its header. The number of possible values is 2^32 = 4,294,967,296, which is approximately 4 billion. These sequence numbers are used to ensure reliable, ordered delivery of packets. Understanding the finite sequence space is important…

Submitted by lukas.cz· Apr 18, 2026Network Forensics

Question

Options

A320 billion
B1 billion
C4 billion
D32 million

How the community answered

(57 responses)

A
7% (4)
B
4% (2)
C
88% (50)
D
2% (1)

Explanation

TCP uses a 32-bit sequence number field in its header. The number of possible values is 2^32 = 4,294,967,296, which is approximately 4 billion. These sequence numbers are used to ensure reliable, ordered delivery of packets. Understanding the finite sequence space is important in security because sequence number prediction attacks (TCP session hijacking) exploit the ability to guess or predict these numbers.

Topics

#TCP/IP#Sequence Numbers#Networking Protocols#TCP Header

Community Discussion

No community discussion yet for this question.

Full 312-49 Practice