flex links instead of stp for connecting other vendor switches ?

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Feb 24th, 2009
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After looking into connecting cisco devices to nortel, the stp may not work, after reading up, would an alternative be to use flex links? can I load balance vlans with this? and also how does it work, does the port have to have a line protocol state of down before it reverts to the backup port ?

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Mohamed Sobair Tue, 02/24/2009 - 09:14
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Why do you think STP wont work? The only reason is that MST (IEEE standard STP) has some incomapatiblity with the PVST+, but if the Switches running RSTP then it would absolutely work fine.

Cisco has developed the way MST interact with PVST+, you can either:

1) run pre-standard MST on Nortel with PVST+ Cisco bridges and have the loadbalancing in place.

2) run standard PVST+ but this disables the loadbalancing scheme.

If you choose (Flex-Link), then its pretty straight foreward, all you have to do is to designate a port as uplink primary while deignat another uplink to be as backup. You will need to activate also preemtion On the main port. with Flex-link you cant loadbalance unfortunately cause one of the port has to be in Standby mode. Unlike STP..



carl_townshend Tue, 02/24/2009 - 12:40
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because on the nortel, they only have one instance of stp running for all the vlans.

what is my solution to this, what would I need to do ?




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