H3C Technologies H3C S5120 Series Switches - Manual (Page 288)

1-1
1
Static Routing Configuration
When configuring a static route, go to these sections for information you are interested in:
z Introduction
z Configuring a Static Route
z Displaying and Maintaining Static Routes
z Static Route Configuration Example
The term “router” in this document refers to a router in a generic sense or a Layer 3 switch.
Introduction
Static Route
A static route is a manually configured. If a network’s topology is simple, you only need to configure
static routes for the network to work normally. 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, the routes will be unreachable and the network breaks. In
this case, the network administrator has to modify the static routes manually.
Default Route
If the destination address of a packet fails to match any entry in the routing table, the packet will be
discarded.
After a default route is configured on a router, any packet whose destination IP address matches no
entry in the routing table can be forwarded to a designated upstream router.
A router selects the default route only when it cannot find any matching entry in the routing table.
z If the destination address of a packet fails to match any entry in the routing table, the router selects
the default route to forward the packet.
z If there is no default route and the destination address of the packet fails to match any entry in the
routing table, the packet will be discarded and an ICMP packet will be sent to the source to report
that the destination or the network is unreachable.
Default routes can be configured by the network administrator via configuring 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.