H3C Technologies H3C SecPath F1000-E - Manual (Page 279)

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Static Route Configuration
NOTE:
The term router in this document refers to both routers and Layer 3 switches.
Static Route Overview
Static Route
A static route is manually configured to forward matching IP packets.
If a network’s topology is simple, you only need to configure static routes to implement network
communication. The proper configuration and usage of static routes can improve network performance
and ensure bandwidth for important network applications.
The disadvantage of using static routes is that they cannot adapt to network topology changes. If a fault
or a topological change occurs in the network, some static routes will be unreachable. In this case, the
network administrator has to modify the static routes manually.
Default Route
Without a default route, a packet matching no routing entry is discarded and an ICMP
destination-unreachable packet is sent to the source.
A default route is used to forward packets that match no entry in the routing table. It can be configured
in either of the following two ways:
• The network administrator can configure a default route with both destination and mask being
0.0.0.0. The router forwards any packet whose destination address fails to match any entry in the
routing table to the next hop of the default static route.
• Some dynamic routing protocols, such as OSPF, RIP and IS-IS, can also generate a default route.
For example, an upstream router running OSPF can generate a default route and advertise it to
other routers, which install the default route with the next hop being the upstream router.
Application Environment of Static Routing
Before configuring a static route, you need to know the following concepts:
1. Destination address and mask
While configuring a static route, specify both the destination IP address and mask in dotted decimal
format.
2. Output interface and next hop address
While configuring a static route, you can specify either the output interface or the next hop address
depending on the specific occasion. The next hop address can not be a local interface’s IP address;
otherwise, the route configuration will not take effect.