Cisco 2960 Redundant Trunk

[ThePetitJean]

Hello,

I need your help

I have this configuration:

Normally for example: Link from Switch A to C: Blocked by spanning tree

How to configure to use all link? To take advantage of the redundance if there are failure and also to have full speed (Ex 2 * 1 Gb) or when the link A to B is full to use also the link A to C.

I hope to be clear in my request ^^

Thansk for your help

Thepetitjean

[Reza Sharifi]

Since you have a physical loop in your topology, in order to stop it you need to use STP.  The other alternative is Flex Link if your devices support it. With Flex link you are still using one link as primary and one as backup.

Have a look at this link for more info:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/flexlink.html

HTH

.

[ThePetitJean]

Thanks for your answer.

STP is actif. To avoid the loop one link is desactivate by STP.

In the two case, one link don't serve.

I suppose is not possible to have this possibilities?

Thanks

[Reza Sharifi]

Correct, STP will block one link to prevent loop.  Now, in your example if switch B and C are 3750 series switches, you can stack them together and connect switch A to both switch B and C using an Etherchannel.  In this case you utilize both links.

HTH

[Ed Willson]

Reza,

    Would it be possible to use PVRST+ rather than STP to load balance the connections and get a theoretical 2Gb connection?

Thanks,

   Ed

[ThePetitJean]

Thanks for your answer.

No stack Possible

Only 2960.

[pjmonline]

you need to create an ether channel using link aggregation to create a 2gb link between switches.

Sent from Cisco Technical Support iPhone App

[Ed Willson]

Jean,

     What did you come up with for your configuration?

Thanks,

    Ed