Operation Manual – Routing ProtocolH3C S7500 Series Ethernet Switches Chapter 1 IP Routing Protocol Overview1-1Chapter 1 IP Routing Protocol OverviewGo to these sections for information you are interested in:z Introduction to IP Route and Routing Tablez Routing Management PolicyNote:When running a routing protocol, the Ethernet switch also functions as a router. Theterm “router” in this document refers to a router in a generic sense or an Ethernetswitch running routing protocols.1.1 Introduction to IP Route and Routing Table1.1.1 IP RouteRouters are used for route selection on the Internet. As a router receives a packet, itselects an appropriate route (through a network) according to the destination addressof the packet and forwards the packet to the next router. The last router on the route isresponsible for delivering the packet to the destination host.1.1.2 Routing TableThe key for a router to forward packets is the routing table. Each router maintains arouting table. Each entry in this table contains an IP address that represents ahost/subnet and specifies which physical port on the router should be used to forwardthe packets destined for the host/subnet. And the router forwards those packetsthrough this port to the next router or directly to the destination host if the host is on anetwork directly connected to the router.Each entry in a routing table contains:z Destination address: It identifies the address of the destination host or network ofan IP packet.z Network mask: Along with the destination address, it identifies the address of thenetwork segment where the destination host or router resides. By performing“logical AND” between destination address and network mask, you can get theaddress of the network segment where the destination host or router resides. Forexample, if the destination address is 129.102.8.10 and the mask is 255.255.0.0,the address of the network segment where the destination host or router resides
