Which of the following scanning method splits the TCP header into several packets and makes it difficult for packet filters to detect the purpose of the packet?

ICMP Echo scanning sends ICMP ping requests to identify live hosts and does not involve TCP flag manipulation or fragmentation.

IP fragmentation allows an attacker to divide the TCP header into separate IP fragments so that a single fragment does not contain enough information for a packet filter or IDS to determine the packet's intent. By fragmenting the SYN and FIN flags across different packets, the scanner evades simple header-inspection rules. Reassembly occurs at the destination, but stateless filters may pass each fragment individually.

ACK flag probe scanning sends ACK packets to probe firewall rules and determine stateful vs. stateless filtering, not to fragment headers for evasion.

IPID scanning (idle scan) exploits the IP Identification field of a zombie host to infer open ports indirectly, and does not fragment TCP headers.