Invalid socket specs, a port number is required: --version

Usage: p0f-analyzer.pl socket-spec ... where socket-spec is an UDP port number optionally preceded by an IP address (or a host name) and a colon. An IPv6 address must be enclosed in square brackets so that the port-delimiting colon is unambiguous. To listen on all interfaces specify an asterisk in place of an IP address, e.g. '*:2345'. A host name 'localhost' implies binding to a loopback interface on any available protocol family (IPv4 or IPv6) and is a default when only a port number is specified. Example usage, all three examples are equivalent: p0f -i eth0 'tcp dst port 25' 2>&1 | p0f-analyzer.pl 2345 p0f -i eth0 'tcp dst port 25' | p0f-analyzer.pl localhost:2345 p0f -i eth0 'tcp dst port 25' | p0f-analyzer.pl [::1]:2345 127.0.0.1:2345