An IP packet has arrived with the first 8 bits as 0100 0010. Which of the…

2014

An IP packet has arrived with the first 8 bits as 0100 0010. Which of the following is correct?

  1. A.

    The number of hops this packet can travel is 2.

  2. B.

    The total number of bytes in header is 16 bytes

  3. C.

    The upper layer protocol is ICMP

  4. D.

    The receiver rejects the packet

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Correct answer: D

The first byte of the IP packet is 0100 0010.

The first 4 bits (0100) represent the IP Version, which is 4 (IPv4).

The next 4 bits (0010) represent the Internet Header Length (IHL), which is 2.

The IHL value indicates the header length in 32-bit words (4 bytes). An IHL of 2 implies a header size of 8 bytes.

However, the minimum valid IPv4 header length is strictly 20 bytes (IHL = 5).

Since 8 bytes is less than the required minimum of 20 bytes, this packet structure is malformed and will be discarded by the receiver.

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