An IP Protocol scan is useful for determining what communication protocols are being used by a host. This information serves different purposes, including packet filtering testing and remote operating system fingerprinting.
This recipe shows how to use Nmap to enumerate all of the IP protocols supported by a host.
Open a terminal and type the following command:
$nmap -sO <target>
The results will show what protocols are supported, along with their states.
# nmap -sO 192.168.1.254 Nmap scan report for 192.168.1.254 Host is up (0.0021s latency). Not shown: 253 open|filtered protocols PROTOCOL STATE SERVICE 1 open icmp 6 open tcp 132 closed sctp MAC Address: 5C:4C:A9:F2:DC:7C (Huawei Device Co.) Nmap done: 1 IP address (1 host up) scanned in 3.67 seconds