Routable Protocols
“Understanding OSI and TCP/IP,” you learned about routable or routed protocols. This book concentrates on TCP/IP, but there are other routable protocols, such as IPX and AppleTalk. These three protocol suites provide sufficient information in the network layer header to allow the router to forward packets from the source node to the destination node even when the router has to forward packets across various networks.
Routing Protocols
Whereas routable protocols provide the logical addressing system that makes routing possible, routing protocols provide the mechanisms for maintaining router routing tables. Routing protocols facilitate inter-router communication, which allows them to share route information used to build and maintain routing tables. Several different routing protocols exist, including Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Enhanced Interior Gateway Routing Protocol (EIGRP). And while these different routing protocols use different methods for determining the best path for packets routed from one network to another, each basically serves the same purpose. They help accumulate routing information related to a speci.c routed protocol such as the Internet Protocol. It is not uncommon to .nd host and server machines running more than one network protocol to communicate. For example, a Windows 2000 (W2K) Server in a domain might be using TCP/IP to communicate with its clients, while at the same time using IPX/SPX to support .le and print servers. Routing protocols also embrace this concept of simultaneously but independently running protocols. Multiple independent routing protocols can run on the same router, building and updating routing tables for several different routed protocols. This means that the same media can actually support different types of networking (e.g., peer-to-peer and client/server).
Routing Protocol Basics
Routing protocols not only provide information for router routing tables, but also have responsibility for determining the best route through an internetwork for packets as they move from the source station to the destination station. Designers have re.ned routing protocols to optimize routes on an internetwork and also to remain stable and show .exibility. They also designed routing protocols to use as little processing overhead as they determine and provide route information. This means that the router itself does not have to have a large multi-processor device to handle the routing of packets. The next section discusses the mechanisms that routing protocols use to determine paths.
“Understanding OSI and TCP/IP,” you learned about routable or routed protocols. This book concentrates on TCP/IP, but there are other routable protocols, such as IPX and AppleTalk. These three protocol suites provide sufficient information in the network layer header to allow the router to forward packets from the source node to the destination node even when the router has to forward packets across various networks.
Routing Protocols
Whereas routable protocols provide the logical addressing system that makes routing possible, routing protocols provide the mechanisms for maintaining router routing tables. Routing protocols facilitate inter-router communication, which allows them to share route information used to build and maintain routing tables. Several different routing protocols exist, including Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Enhanced Interior Gateway Routing Protocol (EIGRP). And while these different routing protocols use different methods for determining the best path for packets routed from one network to another, each basically serves the same purpose. They help accumulate routing information related to a speci.c routed protocol such as the Internet Protocol. It is not uncommon to .nd host and server machines running more than one network protocol to communicate. For example, a Windows 2000 (W2K) Server in a domain might be using TCP/IP to communicate with its clients, while at the same time using IPX/SPX to support .le and print servers. Routing protocols also embrace this concept of simultaneously but independently running protocols. Multiple independent routing protocols can run on the same router, building and updating routing tables for several different routed protocols. This means that the same media can actually support different types of networking (e.g., peer-to-peer and client/server).
Routing Protocol Basics
Routing protocols not only provide information for router routing tables, but also have responsibility for determining the best route through an internetwork for packets as they move from the source station to the destination station. Designers have re.ned routing protocols to optimize routes on an internetwork and also to remain stable and show .exibility. They also designed routing protocols to use as little processing overhead as they determine and provide route information. This means that the router itself does not have to have a large multi-processor device to handle the routing of packets. The next section discusses the mechanisms that routing protocols use to determine paths.