Computer networks routing fundamentals and subnets
2008/7/19 1 Module 10: Routing Fundamentals and Subnets 2008/7/19 2 Outline 10.1 Routed Protocol Routable and routed protocols IP as a routed protocol Packet propagation and switching within a router Internet Protocol (IP) Anatomy of an IP packet 10.2 IP Routing Protocols Routing overview Routing versus switching Routed versus routing Path determination Routing tables Routing algorithms and metrics IGP and EGP Link state and distance vector Routing protocols 10.3 The Mechanics of Subnetting Classes of network IP addresses Introduction to and reason for subnetting Establishing the subnet mask address Applying the subnet mask Subnetting Class A and B networks Calculating the resident subnetwork through ANDing 2008/7/19 3 10.1 Routed Protocol 2008/7/19 4 Routable and routed protocols A routed protocol allows the router to forward data between nodes on different networks. A protocol to be routable, it must provide the ability to assign a network number and a host number to each individual device. IP / IPX NetBEUI ?? 2008/7/19 5 Routable and routed protocols (cont.) 2008/7/19 6 Routable and routed protocols (cont.) The routing table need only contain one entry of 192.168.10.0 instead of all 254 individual entries. 2008/7/19 7 IP as a routed protocol Hierarchical network-addressing scheme. IP is a connectionless, unreliable, best-effort delivery protocol. The term connectionless means that no dedicated circuit connection is established prior to transmission as there is when placing a telephone call. The terms unreliable and best-effort do not imply that the system is unreliable and does not work well, but that IP does not verify that the data reached its destination. This function is handled by the upper layer protocols. IP determines the most efficient route for data based on the routing protocol. 2008/7/19 8 IP as a routed protocol (cont.) 2008/7/19 9 Packet propagation and switching within a router 2008/7/19 10 Packet propagation and switching within a router (cont.)