NAT helps improve security and decrease the number of IP addresses an organization needs. TCP/UDP. Table 3-1 IP Protocols IP Protocol Number Protocol Name 0 HOPOPT 1ICMP 2IGMP 3 GGP 4IP 5ST 6 Generic TCP 7CBT 8EGP 9IGP 10 BBN-RCC-MON 11 NVP-II 12 PUP 13 ARGUS 14 EMCON 15 XNET 16 CHAOS 17 Generic UDP 18 MUX 19 DCN-MEAS Protocol. Header Checksum. A protocol is the pre-defined way that someone who wants to use a service talks with that service. IP addresses: Networks and hosts An IP address is a 32-bit number that uniquely identifies a host (computer or other device, such as a printer or router) on a TCP/IP network. Protocol (UDP, TCP) IP-address of Host A Port number of Host A IP-address of Host B Port number of Host B Whenever a TCP connection has been closed, the association described by the 5-tuple enters a wait state to assure that both hosts have received the final acknowledgement from the closing procedure. 32 bits. Port Number:---> http=80 / https=443 / ftp=20,21 / telnet=23 Protocol number define the field in IP header to which protocol must be delivered. 8 bits. Destination Address. プロトコル番号 ( IP Protocol Number ) プロトコル番号は、上位層のプロトコルを識別するための番号であり、IPヘッダに 8 ビット情報であります。 例えばプロトコル番号が 6 の場合はTCP、17 の場合はUDPとなります。 IPv4 was the first version deployed for production on SATNET in 1982 and on the ARPANET in January 1983. FTP is one of the most commonly used file transfer protocols on the Internet and within private networks. The IP address of the encapsulator, that is, the tunnel entry point. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. An Internet Protocol address (IP address) is a logical numeric address that is assigned to every single computer, printer, switch, router or any other device that is part of a TCP/IP-based network. The IP address is the core component on which the networking architecture is built; no … Set to 4. In Internet Protocol version 6 (IPv6) [RFC1883] this field is called the "Next Header" field.作为Common Sense IP Protocol Number neterpaole 2010-08-05 09:32:00 5034 收藏 Protocol. 16 bits. A Network Address Translator (NAT) is the virtualization of Internet Protocol addresses. Source Address. For each protocol, the protocol index number in the IP header is provided. To better understand how IP addresses and subnet masks work, look at an IP (Internet Protocol) address and see how it is organized. This is a list of the IP protocol numbers found in the field Protocol of the IPv4 header and the field Next Header of the IPv6 header.It is an identifier for the encapsulated protocol and determines the layout of the data that immediately follows the header. Port Number. Description. 20/21. The IP checksum of the outer IP header. 32 bits. The "someone" could be a person, but more often it is a computer program like a Web browser. The IP stands for Internet Protocol, which is the language that computers use to communicate over the Internet. The next header; 4 for the inner IP header, when no intervening tunnel headers are in use. Common protocols of TCP/IP include the following: HTTP (Hyper Text Transfer Protocol) handles the communication between a web server and a web browser. In the world of TCP/IP networking, that identifier is the Internet Protocol (IP) address. File Transfer Protocol (FTP) (RFC 959) TCP. If you’ve worked with computers for any amount of time, you’ve likely been exposed to IP addresses—those numerical sequences that look something like 192.168.0.15. Port number define the number of protocol in an application layer. Internet Protocol version 4 (IPv4) is the fourth version of the Internet Protocol (IP). An FTP server can easily be set up with little networking knowledge and provides the ability to easily relocate files from one system to another. Examples: Protocol Number---> ip=0 / icmp=1 / tcp=6 / udp=17.