bpdu's

[carl_townshend]

are these sent put from the root switch every 2 seconds ?

[Bobby Thekkekandam]

Hi Carl,

Yes, that is correct. More on this here:

Understanding and Tuning Spanning Tree Protocol Timers

http://www.cisco.com/warp/customer/473/122.html

HTH,

Bobby

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[harmanrms]

yes bpdu's are sent every 2 sec that too from the root bridge in the network. they are like any other hello packets.

If a network change occurs in a topology, TCN ie topology cange notifications are sent by the switches towards the root bridge.

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[devang_etcom]

cals bpdus are always send by the root bridge at ever 2 second and other switch will send the TOPOLOGY CHANGE NOTIFICATION BPDU in order to up date the topology change...and you can say the bpdus are one type of hello packet ...and its indication of the available root bridge...you can read about infirior bpdu by searching on cisco.com then it will clear you what is the important of the BPDUS....

hope this helps you

regards

Devang

[devang_etcom]

http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00800c2548.shtml

may you will find good documents on this link

regards

Devang