Which header?

What this networking protocol header identification question tests

This is an easy networking question that asks you to recognize and identify a protocol based on its header structure. It probes whether you can map the physical layout of a packet header to the correct protocol within the OSI model stack.

To answer questions like this, you need to be familiar with the canonical header formats of common protocols across different layers—such as Ethernet, IP, TCP, UDP, and ICMP. The question rewards quick pattern recognition and a solid mental model of how headers differ across the network stack. Many trading systems, especially those dealing with market data feeds or low-latency connectivity, rely on direct socket programming or packet inspection, making this foundational knowledge practical rather than purely theoretical.

• OSI model layers and their protocol families
• Header field layouts and byte ordering
• Protocol-specific identifiers and flags