Q6.Marks: +2.0UGC NET Paper 2: Computer Science 18th June 2024 Shift 1 (Cancelled)
An IPv4 packet has arrived with the first few hexadecimal digits as shown below. How many hops can this packet travel before being dropped ? The data belong to what upper-layer protocol?
To determine the number of hops remaining for the packet and the upper-layer protocol, we need to interpret the given hexadecimal representation of the IPv4 header. Let's break it down step by step.
The given hexadecimal sequence is: 54 00 00 18 00 00 10 00 11 00 04 06 00 01 ...
1. Determine the Time to Live (TTL)
The TTL is located at the 9th byte of the IPv4 header. In the provided sequence, the 9th and 10th digits are 04.
Convert 04 from hexadecimal to decimal:
04 in hexadecimal is 4 in decimal.
This indicates that the packet can travel 4 more hops before being dropped.
2. Determine the Upper-Layer Protocol
The protocol field is located at the 10th byte of the IPv4 header. In the provided sequence, the 10th byte is 06.
The protocol number 06 corresponds to TCP.
Conclusion
The packet can travel 4 more hops, and it belongs to the TCP upper-layer protocol.
