Match the following field lengths:P. UDP Header's Port NumberQ. Ethernet MAC AddressR. IPv6 Next Hea

Q: What is GATE-CS?

GATE-CS is a competitive examination conducted in India. This question is from the 2018 GATE-CS Computer Networks paper.

Q: How can I prepare for GATE-CS Computer Networks?

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This GATE-CS 2018 Computer Networks question has a medium difficulty level and is marked as an important question.

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Question

Match the following field lengths:P. UDP Header's Port NumberQ. Ethernet MAC AddressR. IPv6 Next HeaderS. TCP Header's Sequence NumberI. 48 bitsII. 8 bitsIII. 32 bitsIV. 16 bits

Accepted Answer

Correct Answer: C — P-IV, Q-I, R-II, S-IIIStep-by-step Solution:P. UDP Header Port Number — 16 bits (IV): Both the source and destination port number fields in the UDP header are each 16 bits wide, allowing port values from 0 to 65535 (2¹⁶ − 1).Q. Ethernet MAC Address — 48 bits (I): A MAC address consists of 6 bytes (48 bits), conventionally written as six pairs of hexadecimal digits separated by colons, for example AA:BB:CC:DD:EE:FF.R. IPv6 Next Header — 8 bits (II): The Next Header field in the IPv6 header is 8 bits wide. It identifies the type of header immediately following the IPv6 header (for example, TCP = 6, UDP = 17), serving the same role as the Protocol field in IPv4.S. TCP Header Sequence Number — 32 bits (III): The TCP sequence number field is 32 bits wide, allowing sequence numbers from 0 to 2³² − 1, which enables TCP to number up to approximately 4 GB of data before wrapping around.Why the other options are incorrect:Option D — Assigns R-III (32 bits) to the IPv6 Next Header and S-II (8 bits) to the TCP Sequence Number. Both assignments are reversed: IPv6 Next Header is 8 bits and TCP Sequence Number is 32 bits.Options A and B — Contain multiple incorrect assignments that contradict the standard header specifications.Key Concept: Standard protocol header field sizes: UDP/TCP port number = 16 bits; Ethernet MAC address = 48 bits (6 bytes); IPv6 Next Header = 8 bits; TCP Sequence Number = 32 bits. These values are specified in the respective RFCs and are essential for understanding protocol operation and interoperability.

Match the following field lengths:P. UDP Header's Port NumberQ. Ethernet MAC AddressR. IPv6 Next HeaderS. TCP Header's Sequence NumberI. 48 bitsII. 8 bitsIII. 32 bitsIV. 16 bits

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Match the following field lengths:P. UDP Header's Port NumberQ. Ethernet MAC AddressR. IPv6 Next HeaderS. TCP Header's Sequence NumberI. 48 bitsII. 8 bitsIII. 32 bitsIV. 16 bits

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