net/hping 3.0.0pre1p2 OpenBSD

hping is a command-line oriented TCP/IP packet assembler/analyzer. The interface is inspired by the ping(8) unix command, but hping isn't just for sending ICMP echo requests. It supports TCP, UDP, ICMP and RAW-IP protocols, has a traceroute mode, the ability to send files in a covert channel, and many other features. While hping was mainly used as a security tool in the past, it can be used in many ways by people that don't care about security to test networks and hosts. A subset of the stuff you can do using hping:

• Firewall testing Advanced port scanning
• Network testing, using different protocols, TOS, fragmentation
• Manual path MTU discovery
• Advanced traceroute, under all the supported protocols
• Remote OS fingerprinting
• Remote uptime guessing
• TCP/IP stacks auditing

N.B. the message "[send_ip] sendto: No route to host" often indicates that sending a packet has been blocked by PF on the local machine.