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question about RSTP

Hi !

I currently studing for my CCNP certification .

Questions on RSTP :

I not sure I'm correctly understand the difference between alternate and backup port. When I had read on it I had suppose wasd correctly understood, but in lab (I use 4 switchs 2 2950 and 2 2960 connected each others) and none port as mount as backup role all blocking was alternated.

Was I understand correctly ? The root RSTP network flood BPDU on his designated port at regular basic (HELLO-TIME) is non-root switch received BPDU from root it relayed this BPDU but if it not received BPDU from root it generate BPDU and this one ?? what this BPDU contain (information about the root it self for example ?) If it is what this switch is made I suppose the switch it not send thoose BPDU on his root port ?

I' not understand the compatibility process between the 802.1d and 802.1w protocol detection and timers...

Is exist some differences between TCN BPDU, TC BPDU and TCA BPDU those appear the sames in some documents for me and differents in others... I one document I was understant 802.1d is able to understabt 802.1w TC/TCA BPDU but 802.1w send also TCN BPDU for compatibility issue with 802.1d....

In case of indirect link failiure should I suppose to able to view RLQ packets pass between siwtches with some sniffer software? I was connected between them on a hub I was see STP packet to orphelin switch advertsign it self as a new root but nothing about RLQ

What system are use to notifying Topology Change and what is different when a RSTP switch is connected with STP legacy switch ? When the TC timer is use and is not. I my documentation some time they are talk about TCN BPDU for legacy switch and TC BPDU is it the same thing or not what is the difference ? And if they are different why 802.1d understand

for my studdy I read the following Cisco documentation :

Understanding Rapid Spanning Tree

Protocol (802.1w)

Understanding and configuring STP

Understanding and configuring Backbone Fast on Catalyst Switches doc ID 12014

And finally BCMSN official document from Cisco Press.

Excuse me it maybe my English, I'm a French peoples, sometimes English documents are confuse for me I had to aks someone to explain to me in others words...

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