TCP/IP protocols include:
- FTP - File Transport Protocol at the application layer.
- Telnet - Remote session at the application layer.
- SMTP - Simple Mail Transport Protocol at the application layer.
- DHCP - Dynamic host configuration protocol is used to assign IP addresses dynamically to network cards. It works at the application layer.
- TCP - Transport Control protocol is a connection oriented reliable protocol working at the transport layer.
- UDP - User Datagram Protocol is a connection less unreliable protocol working at the transport layer.
- ICMP - Internet Control Message Protocol is used to perform network error reporting and status. It works at the transport layer.
- IGMP - Internet Group Management Protocol is used to manage multicast groups and it works at the transport layer.
- IP - Internet Protocol is used for software addressing of computers and works at the data link layer.
- ARP - Address Resolution Protocol is used to resolve the hardware address of a card to package the ethernet data. It works at the data link layer.
- RARP - Reverse Address Resolution Protocol used for disk less computers to determine their IP address using the network. It works at the data link layer.
These give a sample of some of the TCP/IP protocols and there are many more.
Class A-E networks
The addressing scheme for class A through E networks is shown below. Note: We use the 'x' character here to denote don't care situations which includes all possible numbers at the location. It is many times used to denote networks.
|Network Type||Address Range||Normal Mask||Comments|
|Class A||001.x.x.x to 126.x.x.x||255.0.0.0||For very large networks|
|Class B||128.1.x.x to 191.254.x.x||255.255.0.0||For medium size networks|
|Class C||192.0.1.x to 223.255.254.x||255.255.255.0||For small networks|
|Class D||224.x.x.x to 188.8.131.52|
|Class E||240.x.x.x to 247.255.255.255|
RFCs 1518 and 1519 define a system called Classless Inter-Domain Routing (CIDR) which is used to allocate IP addresses more efficiently. This may be used with subnet masks to establish networks rather than the class system shown above. A class C subnet may be 8 bits but using CIDR, it may be 12 bits.
There are some network addresses reserved for private use by the Internet Assigned Numbers Authority (IANA) which can be hidden behind a computer which uses IP masquerading to connect the private network to the internet. There are three sets of addresses reserved. These address are shown below:
- 172.16.x.x - 172.31.x.x