A penetration tester was assigned to scan a large network range to find live hosts. The network is known for using strict TCP filtering rules on its firewall, which may obstruct common host discovery

ICMP Timestamp Ping Scans, while using ICMP, can still be blocked by firewalls that filter general ICMP traffic, making them unreliable for bypassing strict firewall rules.

ICMP ECHO Ping Scans are the most common form of ping and are frequently blocked by firewalls as a basic security measure, failing to bypass strict filtering.

TCP SYN Ping Scans rely on sending TCP SYN packets, which would be directly blocked by firewalls with 'strict TCP filtering rules' as explicitly stated in the question.

A UDP ping scan sends UDP packets to common ports and expects an ICMP Port Unreachable message from live hosts with closed ports, or an application-level response from open ports. This technique effectively bypasses firewalls with strict TCP filtering rules because it operates at the UDP layer, which may have different, less restrictive filtering policies compared to TCP.