3com 10014299 Mode D'Emploi

This chapter covers the following topics:

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To enhance a network's reliability, 3Com routers provide perfect standby functions 
through the use of standby centers

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Interfaces that have standby are called main interfaces. Every physical interface 
or sub-interface on a router can serve as a main interface. A logic channel, such 
as X.25 or frame-relay virtual circuits, on any interface can also serve as a main 
interface.

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The interfaces serving as the standby for other interfaces are called standby 
interfaces. Any physical interface or logic channel on an interface of a router 
can serve as the standby interface of another interface or logic channel.

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One main interface can have several standby interfaces; if the main interface 
goes down work resumes on a standby interface, based on priority.

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Interfaces (such as ISDN BRI and ISDN PRI interfaces) that have multiple physical 
channels can provide standbys to multiple main interfaces by using dialer route.

Standby centers support the standby load sharing function. When the traffic of 
the all-active interfaces on the standby center reaches the set enable threshold, 
routers will start a standby interface with the highest priority to share the load 
with the started interfaces. When the traffic of all active interfaces on the standby 
center is less than the set disable threshold, routers close the standby interface 
with the lowest priority.

Standby center configuration includes:

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On a 3Com router, not only every physical interface or sub-interfaces of the router, 
but every virtual circuit of X.25 or frame relay can work as a main interface. If the