1 static route configuration, Introduction to static route, Static route – H3C Technologies H3C S3100 Series Switches User Manual
Page 105: Default route, Static route configuration
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Static Route Configuration
When configuring a static route, go to these sections for information you are interested in:
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Displaying and Maintaining Static Routes
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Troubleshooting a Static Route
Introduction to Static Route
Static Route
Static routes are special routes. They are manually configured by the administrator. In a relatively
simple network, you only need to configure static routes to make routers work normally. Proper
configuration and usage of static routes can improve network performance and ensure sufficient
bandwidth for important applications.
When the network topology changes, static routes may become unreachable because they cannot
adapt themselves to the change automatically, thus resulting in network interruption. In this case, the
network administrator needs to modify the configuration of static routes manually.
Static routes are divided into three types:
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Reachable route: normal route. If a static route to a destination is of this type, the IP packets
destined for this destination will be forwarded to the next hop. It is the most common type of static
routes.
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Unreachable route: route with the reject attribute. If a static route to a destination has the reject
attribute, all the IP packets destined for this destination will be discarded, and the source hosts will
be informed of the unreachability of the destination.
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Blackhole route: route with blackhole attribute. If a static route destined for a destination has the
blackhole attribute, the outgoing interface of this route is the Null 0 interface regardless of the next
hop address, and all the IP packets addressed to this destination will be dropped without notifying
the source hosts.
The attributes reject and blackhole are usually used to limit the range of the destinations this router
can reach, and help troubleshoot the network.
Default Route
To avoid too large a routing table, you can configure a default route.
When the destination address of a packet fails to match any entry in the routing table,
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If there is default route in the routing table, the default route will be selected to forward the packet.
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If there is no default route, the packet will be discarded and an ICMP Destination Unreachable or
Network Unreachable packet will be returned to the source.