Netgear XCM8810 Chassis User Manual - Page 597

NETGEAR 8800 User Manual Once a routing protocol is configured, dynamic routes require no configuration and are automatically updated as the network changes. Static Routes Static routes are routes that are manually entered into the routing tables and are not advertised through the routing protocols. Static routes can be used to reach networks that are not advertised by routing protocols and do not have dynamic route entries in the routing tables. Static routes can also be used for security reasons, to create routes that are not advertised by the router. Static routes are configured in the XCM8800 software, remain part of the configuration when the switch is rebooted, and are immediately available when the switch completes startup. Static routes are never aged out of the routing table. A default route is a type of static route that identifies the default router interface to which all packets are routed when the routing table does not contain a route to the packet destination. A default route is also called a default gateway. Multiple Routes When there are multiple, conflicting choices of a route to a particular destination, the router picks the route with the longest matching network mask. If these are still equal, the router picks the route using the following default criteria (in the order specified): • Directly attached network interfaces • Static routes • ICMP redirects • Dynamic routes • Directly attached network interfaces that are not active. Note: If you define multiple default routes, the route that has the lowest metric is used. If multiple default routes have the same lowest metric, the system picks one of the routes. You can also configure blackhole routes-traffic to these destinations is silently dropped. The criteria for choosing from multiple routes with the longest matching network mask is set by choosing the relative route priorities. Relative Route Priorities Table 57 lists the relative priorities assigned to routes depending on the learned source of the route. Chapter 20. IPv4 Unicast Routing | 597