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Uplinkfast

Hello,

Can uplinkfast be configure in one switch that has 2 uplinkt to another switch (root) or for uplinkfast to work the uplinks have to be connected to two different switches? I have only two switches in my home-lab and I am trying to see how it works but connecting two linkst between the two switches it still goes trough forward delat times even though uplinkfast is enabled.

Please help me get this clear.

3 REPLIES
VIP Super Bronze

Re: Uplinkfast

Hi,

Uplink fast speed up the convergence when you have an access switch connected two distro switches not 2 links connecting to the same switch.

You can also verify that it is enabled by issuning the command "show spanning-tree"

have a look at this doc for more details

http://conft.com/en/US/tech/tk389/tk621/technologies_tech_note09186a0080094641.shtml

HTH

Reza

Hall of Fame Super Gold

Re: Uplinkfast

If you want two uplink ports to go up quickly then put then into dot1q trunking.

Re: Uplinkfast

Hello,

Can uplinkfast be configure in one switch that has 2 uplinkt to another switch (root) or for uplinkfast to work the uplinks have to be connected to two different switches? I have only two switches in my home-lab and I am trying to see how it works but connecting two linkst between the two switches it still goes trough forward delat times even though uplinkfast is enabled.

Please help me get this clear.

Hi,

The UplinkFast feature is based on the definition of an uplink group. On a given switch, the uplink group consists in the root port and all the ports that provide an alternate connection to the root bridge. If the root port fails, which means if the primary uplink fails, a port with next lowest cost from the uplink group is selected to immediately replace it.

The UplinkFast feature dramatically decreases the convergence time of       the STP in the event of the failure of an uplink on an access switch.       UplinkFast interacts with other switches that have a strict standard STP.       UplinkFast is only effective when the configured switch has some       non-self-looped blocked ports. In order to increase the chances to have blocked       ports, the port cost and bridge priority of the switch are modified. This       tuning is consistent for an access switch, but is not useful on a core switch.

UplinkFast only reacts to direct link failure. A port on the access       switch must physically go down in order to trigger the feature

Hope to Help !!

Ganesh.H

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