Operation Manual – Routing ProtocolH3C S5600 Series Ethernet Switches Chapter 1 IP Routing Protocol Overview1-5Routing approach PrioritySTATIC 60RIP 100OSPF ASE 150OSPF NSSA 150UNKNOWN 255BGP 256Note:z The smaller the priority value, the higher the priority.z The priority for a direct route is always 0, which you cannot change. Any other typeof routes can have their priorities manually configured.z Each static route can be configured with a different priority.1.2.4 Load Sharing and Route BackupI. Load sharingA given routing protocol may find several routes with the same metric to the samedestination, and if this protocol has the highest priority among all the active protocols,these routes will be considered valid and are used to forward packets, thus achievingload sharing.II. Route backupYou can configure multiple routes to the same destination, expecting the one with thehighest priority to be the primary route and all the rest backup routes.Route backup can help improve network reliability. Automatic switching can happenbetween the primary route and a backup route.Under normal circumstances, packets are forwarded through the primary route. Whenthe primary route goes down, the route with the highest priority among the backuproutes is selected to forward packets. When the primary route recovers, the routeselection process is performed again and the primary route is selected again toforward packets.1.2.5 Routing Information SharingAs different routing protocols use different algorithms to calculate routes, they maydiscover different routes. In a large network with multiple routing protocols, it is
