About Uplinkfast.....

[hyukin.kwon]

Hi all,

I have two Cat 6509 and a Cat 2948. They are phsically in loop state.

So I'd like to enable uplinkfast . From this , I have a qustion .

Is it possible to get an effect to enable uplinkfast only on 22948 not on two 6509 ? Of course Two 6509's STP are on.

Until now I know that the 3 switches must have uplinkfast in common .

Is it right ?

Thanks in advance and Best Regards.....

[Prashanth Krishnappa]

Uplink Fast works only when the switch has blocked ports. The feature is typically designed for an access switch having redundant blocked uplinks. I'm assuming your 6509's are the core and are roots for Spanning tree. If this is the case, you'll need to enable uplinkfast only on your CAT2948G. The following is an excellent tech tip on Uplinkfast feature

http://www.cisco.com/warp/public/473/51.html

[p.fligman]

Hi,

assume 2948 is access layer switch dual homed to core 6509s. As well as uplink fast only enabled on 2948g uplinks, you'll also need to enable backbonefast between 6509s (will allow blocked 2948 uplink to change to forwarding when link between 6509 fails). Otherwise coz 2948 has no visiblity of failed link then eill not be able to get to devices connected on 6509 that is behind normal blocked link.

Regards

Pete

[shuailm]

Just enable uplinkfast only on two 2948.