3com S7906E Manuel De Montage

Page de 2621
 
1-1 
1  
Static Routing Configuration 
When configuring a static route, go to these sections for information you are interested in:  
 
 
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. 
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. 
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 in two ways: