IP protocol number | Article about IP protocol number by The Free Dictionary
IP protocol number
IP protocol numberThe 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)
References in periodicals archive
It sees only an IP protocol number
and must be either allowed or blocked, without knowing any more details regarding the content of the packet.