Cisco Systems 3560 Manual Do Utilizador

When a router has two or more routes to the same network with the same metrics, these routes can be 
thought of as having an equal cost. The term parallel path is another way to see occurrences of equal-cost 
routes in a routing table. If a router has two or more equal-cost paths to a network, it can use them 
concurrently. Parallel paths provide redundancy in case of a circuit failure and also enable a router to 
load balance packets over the available paths for more efficient use of available bandwidth.

Even though the router automatically learns about and configures equal-cost routes, you can control the 
maximum number of parallel paths supported by an IP routing protocol in its routing table. Although the 
switch software allows a maximum of 32 equal-cost routes, the switch hardware will never use more than 
16 paths per route.

Beginning in privileged EXEC mode, follow these steps to change the maximum number of parallel 
paths installed in a routing table from the default:

Use the no maximum-paths router configuration command to restore the default value.

Static unicast routes are user-defined routes that cause packets moving between a source and a 
destination to take a specified path. Static routes can be important if the router cannot build a route to a 
particular destination and are useful for specifying a gateway of last resort to which all unroutable 
packets are sent. 

Beginning in privileged EXEC mode, follow these steps to configure a static route:

Use the no ip route prefix mask {address | interface} global configuration command to remove a static 
route.

Enter global configuration mode.

router {bgp | rip | ospf | eigrp} 

Enter router configuration mode.

maximum-paths maximum

Set the maximum number of parallel paths for the protocol routing 
table. The range is from 1 to 16; the default is 4 for most IP routing 
protocols, but only 1 for BGP.

Return to privileged EXEC mode.

Verify the setting in the Maximum path field.

(Optional) Save your entries in the configuration file.

Enter global configuration mode.

ip route prefix mask {address | interface} [distance] 

Establish a static route.

end 

Return to privileged EXEC mode.

Display the current state of the routing table to verify 
the configuration.

(Optional) Save your entries in the configuration file.