Types of Routing Protocols & Basic Routing Protocols

Protocols are the language used by computers and routers to communicate with each other. Different systems can employ different network operating systems, which in turn, use different protocols for managing the flow of data between computers and other network devices. Additionally, some protocols can be routed over the Internet, while others are mainly used for local area network (LAN) communications.
What Are Protocols?
Each protocol can be considered a type of "language". Different computer systems can have or use different protocols to communicate with one another.
TCP/IP
All computers and networks that transmit on the Internet must use Transmission Control Protocol/Internet Protocol (TCP/IP); this is a connection-oriented protocol that employs error checking and data flow control.
Apple Talk
Apple talk is a protocol designed to connect Macintosh computers; it can also be routed and combined with Windows/Microsoft based networks.
IPX/SPX
IPX/SPX stands for Internetwork Packet Exchange/Sequenced Packet Exchange, which was designed by Xerox in the 1980s. Later, IPX/SPX was changed and enhanced by Novell for use in their Netware network operating system.
NetBEUI
NetBIOS extended user interface (NETBUI) was developed by IBM and Microsoft; it is a small, fast, and efficient networking protocol that consumes few system resources.
DHCP
Dynamic Host Control Protocol is in use by nearly every computer connected to the Internet. DHCP automatically assigns IP addresses to computers and virtually eliminates the possibility of duplicates.

Basic Routing Protocols

Routers operate on layer 3 of the Open System Interconnection Reference Model, usually referred to as the OSI Model. Protocols are the language that routers use when speaking to each other. All routers operate on layer 3 of the OSI model and are capable of using multiple protocols such as RIP, IGRP/EIGRP, OSPF and BGP. Each of these protocols have advantages and disadvantages. Each protocol also has an ideal use, whether it is a small or large network.


RIP
Routing Information Protocol was originally designed for XEROX PUP, PARC Universal Protocol. It became a part of networking when it was defined in RFC 1058 in 1988. RIP is a widely used open protocol that is easy to configure and good for use in small networks. If RIP is used on a large network with many paths, and more than 16 hops RIP will leave a lot to be desired. In small networks, RIP is the preferred protocol because of the ease of use.
EIGRP/IGRP
Interior Gateway Routing Protocol was developed by Cisco in the mid 1980s as a proprietary protocol to negate the problems seen with RIP. In the early 1990s Cisco developed EIGRP as a way to overcome the limitations seen in RIP and IGRP. According to Cisco, IGRP will be removed from their IOS, Internetwork Operating System, which Cisco uses to control for their routers. EIGRP is good for networks of all sizes and is very easy to configure.
OSPF
OSPF, Open Shortest Path First, was developed by the Interior Gateway Protocol (IGP) working group of the Internet Engineering Task Force (IETF). Since it was developed by IETF, it is an open protocol, not a proprietary one. OSPF is more complicated and not as easy to use as RIP since it uses link-state routing. Link-state routing is that every node constructs a map of the connectivity to the network in the form of a graph. This way the router knows which nodes are connected to which other nodes.Link-state advertisements are sent to all devices, which causes an initial flood. After the initial flood from the setup phase OSPF is very efficient in operation. It uses three different databases for neighbors, link states and routes.
BGP
Border Gateway Protocol, BGP, is the standard protocol that the Internet operates on. This protocol is not usually used on small home networks or even larger business networks due to the complexity of setting it up. While it is an open protocol, everything is manual, including neighbors, which is automatic with all of the other protocols discussed here. This is only included for reference as it is very unlikely that the average home user will ever come in contact with this protocol.