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Load balance and Back up


We have configured load balancing for a serial link in OSPF. We are using one PRI channel for that. Is is possible to configure a back up for this serial link from PRI channel. ( using unused channel from PRI ).

we have used follwoing commad in serial link configuration.

backup load 60 40 ( for load balancing )

backup interface dialer 100 ( one of the PRI channel for load balancing ).

can i asign one channel from PRI as a backup if this serial line fails. Or if serial line fails load balance channel will trigger and act as a backup ? Can i configure both load balance as well as backup , if leased serial line fails.

Thanks in advance


Hall of Fame Super Silver

Re: Load balance and Back up


When you configure load balancing (or load sharing) you automatically get backup. With load balancing there will be two separate paths to the destination in the routing table. If one of the paths fails and is withdrawn from the routing table then all traffic will be sent on the remaining path.

The configuration that you have posted here is defining a channel of the PRI as backup (with the backup interface command) and by using the backup load command you have also indicated that if the primary link gets over a configured load threshold that the PRI should activate and share the load.

So this gives you both backup and load share.