Traffic Redundancy between switches

Unanswered Question
Apr 2nd, 2009

Hello Guys,

I need suggestions from you all on attached proposed setup.

Actually I have three switches in network(Switch A,B,C). Switch A is the parent(main) switch from where two switches(B & C) connected for access node.

I am looking for solution where in case of failure of main uplinks i.e link between Switch A to B or between Switch A to C , L2 traffic of isolated switch diverted on direct path between Switch B & Switch C and then to uplink towards main switch A.

I have this problem too.
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glen.grant Thu, 04/02/2009 - 10:41

If you have spanning tree running , it should automatically take care of that situation assumeing all the vlans on b and c are allowed on the trunk between b and c. Make sure the root of all vlans are on switch "A" .

ralphcarter Thu, 04/02/2009 - 18:35

As Glen said, spanning-tree will take care of the redundancy for you. Make sure you set switch A as your root bridge for all vlans.

Also, if you can, try to run Rapid Spanning-tree instead of the old 802.1d. Your failover will be lightning fast as compared to 802.1d.

Single step on EACH switch:

# spanning-tree mode rapid-pvst

Do "show spanning-tree vlan 1" (or whichever vlan) and this will tell you which ports are blocked for the specific vlan. Fri, 04/03/2009 - 00:36

@ Glen,

You mean excute below command of Switch "A"

spanning-tree vlan 1,2,3,4,5,6,7 root

One more thing....PVST is running on all switches.




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