Embedded checksums apply to which protocols and where calculated?

Embedded checksums apply to which protocols and where calculated?

• A. TCP, UDP, ICMP; calculated at the destination
• B. TCP, UDP; calculated at the destination
• C. ICMP only; calculated at the destination
• D. UDP, ICMP; calculated at the source

Answer: (C)

Embedded checksums are checksums that appear inside the payload of a message rather than in the protocol header. ICMP is the protocol where you commonly see this, because ICMP error messages carry a portion of the original IP header (which itself includes a checksum) inside the ICMP payload. The destination end processes and verifies that embedded header by checking its checksum, ensuring the embedded data hasn’t been corrupted. TCP and UDP have their own checksums over the transport data with a pseudo-header, but they don’t rely on an embedded checksum inside the payload in the same way as ICMP. So, embedded checksums apply to ICMP, and they are calculated/verified at the destination.

Embedded checksums are checksums that appear inside the payload of a message rather than in the protocol header. ICMP is the protocol where you commonly see this, because ICMP error messages carry a portion of the original IP header (which itself includes a checksum) inside the ICMP payload. The destination end processes and verifies that embedded header by checking its checksum, ensuring the embedded data hasn’t been corrupted. TCP and UDP have their own checksums over the transport data with a pseudo-header, but they don’t rely on an embedded checksum inside the payload in the same way as ICMP. So, embedded checksums apply to ICMP, and they are calculated/verified at the destination.