IP protocol number
IP protocol number
The numeric identification of the upper layer protocol that an IP packet should be sent to. The number is stored in the header that is prefixed to an IP packet. Note that the IP protocol number is not the same as the port number (see TCP/IP port), which refers to a higher level, such as the application layer. Following are some of the common IP protocol numbers.IPProtocol # PurposeTCP 6 Transport type UDP 17 Transport type ICMP 1 Control message IGMP 2 Multicast EGP 8 Exterior gateway IGP 9 Interior gateway RSVP 46 Reserve bandwidth IP 4 Encapsulation (IP in IP)