STP and RSTP Convergence

Hi
I'm studying for the ICND exam and have a basic question for some one. After STP/RSTP has converged what ports recieve BPDU. Is it all ports on all switches that are part of the active topology or just the trunk ports. If there is a hub connected to the topology do all hub ports recieve the BPDU?
I wish I had a diagram to make my question clearer.
I would appreciate any advice.
Gavin

All ports forward\recieve BPDUs. If you use a network monitor\capture program such as Etherreal you can view the BPDUs that are recieved on your port. BPDUs are sent\recieved on active and STP disabled ports, the disabled ports just don't act as a forwarding port for normal traffic. This is so that spanning-tree can keep an accurate loop free topology.
Hope that helps

Similar Messages

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    Hi!
    The problem is that the 2950 is not really running RSTP but Rapid-PVST. This is PVST with each vlan running an RSTP instance. MST was designed to interact with the IEEE version of RSTP, that only feature a single instance for all the vlans.
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    - Another solution is to avoid trunking between the Rapid-PVST and the MST region (we can run RSTP between a Rapid-PVST bridge and an MST region on an access port).
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  • Problems sending audio to and from STP and then back into FCP

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  • Logic Studio: Anyone using STP and WaveBurner to "master" L8  material?

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  • MSTP and RSTP

    Can someone pls tell me the difference between MSTP and RSTP...Any good url will be of great help..
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    Hi Ammavan,
    The following URLs are good for MSTP and RSTP.
    MSTP: http://www.cisco.com/warp/customer/473/146.html
    RSTP: http://www.cisco.com/warp/customer/473/147.html
    RSTP is an evolution of 802.1d spanning tree protocol. The logical topology that the network converges to with RSTP/MSTP is the same as what the network would converge to with 802.1d. However, there are several changes in the RSTP protocol including a new BPDU format, port role changes, how switches handle the BPDUs etc. The above link gives more details on each of these changes.
    RSTP builds just one logical topology for all vlans. However with the Cisco implementation, similar to PVST+, RSTP is implemented as R-PVST+. What this means is that we will run a separate RSTP instance for each vlan. Hence we can load balance in this way.
    MSTP is built on top of RSTP. One key difference is that MSTP allows you to group a set of vlans into a particular instance. Hence if you have a thousand vlans, you can group half of the vlan into instance 1 and the other half in instance 2. Hence there will be two instances of spanning tree running in the network then.
    Hope this is not too confusing. Please read the above links and if you have any questions, please write in and I will try and explain more in detail.
    regards
    -Alok

  • PVST+ and RSTP

    Hi All,
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  • STP and Loop Guard

    Hi everyone, I've a question for you guys:
    Please check this topology: http://www.cisco.com/warp/public/473/84d.gif
    I've read that you must enable loop guard on every nondesignated port (root and alternate ports) to prevent unidirectional related loops. I understand the situation where switch C unblooks the AP port and cause a loop. But what if the link is not unidirectional, what if switch B has some problem and indeed switch C should forward traffic to the segment C-B? Is there a difference between the link going down (disconected)and just stop seeing BPDUs?
    Also, why would anyone configure loop guard on a root port? If for example, SWC stops seeing BPDUs from SWA, what would loop guard do? put the port in a block state or it would recalculate its Root port (port to SWB) and put the port to SWA into a designated state (after not receiving BPDS from SWA)? I'm very confused, any help would be greatly apretiated.
    Omar Montes

    The assumption made by STP is that if a link is not able to transmit BPDU, it is down. So if there is bidirectional link failure, the case is natively handled by STP. If there is only unidirectional link failure, you could end up with a unidirectional loop (which is about as bad as a bidirectional loop;-))
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    Configuring loopguard on a designated port will not cause any problem anyway, so in fact you can configure loopguard blindly on all the port.
    The IEEE introduced a feature (the dispute mechanism) that works much better than loopguard in order to protect against unidirectional link failure. However, this mechanism requires an RSTP bpdu format. It is currently only implemented in MST on cisco switches (it will be soon available in rapid-pvst). No need to use loopguard with the latest MST code at least.
    Regards,
    Francois

  • Question in switching for STP and loop

    hi ,
    i have a question in loop issue , will it occur in this case or not
    i will describe my scenario as below :
    now i have 4 switches connected with full mesh.
    =================
    3 of them has stp protocol enabled
    only 1 of them is un manged and dont support STP protocol
    ====================================
    the question is :
    if i connected the 4 switches full mesh  , will  the loop occurs ??
    as i believe , stp loop prevention depend on the switch itself not on their neighbour ,  but not sure from my understanding
    wish to help
    regards

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    Posting
    If there's only one or two non-STP switches, in a full mesh, you'll be okay.  Once you have at least three non-STP switches, in a full mesh, you have a loop between them.

  • Audio exporting problems: from FCP to protool/STP and back again

    --------------------------------------------------------------------------------
    Final Cut Pro sound export for mastering.....sync problem
    Hey,
    I'm editing a 30 minute film and I have done most of the sound edit in FCP and Soundtrack pro and I want to now bring all the sound into pro tools to master the sound but every time i export sound into pro tools it seems to stretch by two or three seconds.
    I have tried OMF, AIFF, XML, and Quicktime audio file sut to no avail!!!!
    There are 50 tracks in the file so it is quiet large. It's not that there are handles of the file also as when I sync the file with the audio track with the video it syncs in one place but it is still out of sync in another.........It's as if the audio has been stretched!?!
    If anyone has any advice it'd be much appreciated
    Keith

    Check the timecode rate and sync options in Protools. It sounds like a timecode or samplerate mismatch.
    Especially note that 23.976fps OMFs from FCP (probably STP as well) show up in Protools as 24fps sessions. Change the PTs timecode to 23.976 to realign.

  • Simple, basic issue - Sending a few clips at once from FCP to STP and back.

    Hi,
    I'm working on a 20 minute video, already cut, hoping to do some simple sound reduction on a few clips.
    One scene has two video clips from the same camera shot, wind noise on the audio.
    Can I send two or more clips to STP at the same time?
    When I try that, the whole 1 hour tape (I did a batch capture) appears in the STP timeline.
    Is there a way to send the clips so only those clips go to STP, not the whole original clip in the browser?
    Once I do the noise reduction, why can't I get it to automatically apply to the clips in FCP?
    I must be doing something wrong, but I don't know what.
    Any ideas, anyone?
    Thanks!

    Multi-track projects won't behave like audio file projects, with automatic updates in FCP. Once you have saved the project, export a mix, and you can send it back to your FCP timeline in the dialog box.

  • Solving STP and VTP in DC enviornment

    hi,
    i m having 2 65xx Core switches with me and around 10 49xx and 10 3560 switches with me ..connected in a triangle (65xx with etherchaneel and all rest of switches with dual connection to both the core switches.
    need to know what is the best way to configure them so as to avoid STP loops and also for VLAN's flow .
    shall i divide the switches in half and make both the core as root ...or one as root ...
    Kindly Help...

    Well my opinion would be to go ahead with your design. Keeping it simple is the key only configure MST or RPST if you know what your doing with the config. PVST+ is simple and enabled by default. And as you say it is a Datacentre, i believe your design would be final in these cases just go ahead with PVST+. Use VTP transparent mode on all your access switches. This way you can keep control of the vlan information passing to your access switches. The core can run on VTP Transparent too.
    Redundancy is an important factor. As you have mentioned you are using your 6500 as core, just another question are you having a single sup or double sup engine?
    For your HSRP do load sharing across your core switches odd vlans given higher priority in Primary Core and even vlans given higher priority in Secondary core. Similary do remember the spanning-tree priority command.
    For example vlan 10 which is having higher HSRP priority on Core Switch 1 should also have spanning-priority lower i.e probably keep it as 8192 and this spanning priority for Vlan 10 on Switch 2 should be 16384. Load share your layer 2 also across switches.
    HTH
    Hoogen
    Do rate if this helps :)

  • STP and VTP ?

    Hello,
    can any one clear my below doubts,
    1)Does STP(or PVST,or PVST+) enabled default on the switches.If yes then how can we disable it(just to know about this)
    2)Does VTP enabled default on switches if yes then how to disable it.
    Please reply ASAP.

    Hi chand,
    From your post,
    You can disable STP by:
    no spanning-tree vlan X
    so this,
    no spanning-tree vlan X is a global mode command?
    then what is the command to disable PVST,PVST+,RSTP?
    Waiting for your reply..

  • STP and Metadata

    Hi,
    Any ideas on how to assign metadata to wav files I edited in STP (from a live performance)?
    I've tried several things (e.g., converting wav to Apple Lossless in iTunes) but when I burn a disc and put the disc in another machine (with iTunes), I get nothing but Track 01, etc. Thoughts?
    mp

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    Looks like DP 5.1 has Mackie Control surface support.
    I tried some more STP using a quicktime movie (very basic, capture from DV, Export to Quicktime Movie) -- if I add this Movie to STP I get no audio.
    If I create a new STP project with just audio files, all works including setting output channels for 5.1 work and I see my 14 channels of output (what the Motu supports).
    As soon as I add the any QuickTime Movie create by FCP, my audio goes away and I only see two available channels. It is as if there is something in the QuickTime 7 movie that is completely messing up audio output channels on my Motu. Motu's site mentions using QuickTime 6 because Apple modified how the audio works in QuickTime 7, but I would think Apple's own STP should be able to deal with this??
    I'll give STP & FCP another days worth of trying to make it work, but my project has been stalled for over a week now with this problem so I need to find a solution even if that involves buying other software. But I'm definitely on "edge" now as my level of frustration is peaking with STP.
    I send a formal bug/issue to Apple on this, but I doubt I'll get any response (never got even a confirmation last time I reported a bug) regardless of how much money I've spent on Apple hardware/software.
    Thanks for the suggestion, Rob.

  • STP and GLBP

    What is the recommended STP priorities if GLBP is going to be used with a redundant core/dist...

    GLBP is not recommended in Layer 2 looped designs with blocking links at the access layer.
    GLBP is best when there is no L2 connection between the Dist switches, only L3. This non-looped approach leaves both uplinks forwarding from the access switch and no matter which switch GLBP selects as the default gateway it is only one hop away.
    Hope this help. Please rate all helpful posts. :)
    -Brad

  • STP and Link Identification

    Hi All,
    STPs job, is to indentify links and manage possible loops in redundant networks(correct me if I'm wrong). I can attach a number of switches, that aren't using vlans(meaning no trunk links) just by attaching cables to and fro. Then, of course, I can have vlan enabled switches, that are interconnected via trunk links. Does STP distinguish between the two, and how..? I'm looking for a more detailed analysis of how it does this. CCNA Intro/ICND books don't explain well the difference, if 1 exists. Cheers.
    coolboarderguy...

    Hello,
    STP does not distinguish between trunk links or access links. It listens to BPDU's (Bridge Protocol Data Units), if those are present on a port, the port will participate in the STP process. So, you could disable STP for all VLAN's on a trunk, and the trunk would not participate in STP.
    Or, in CCO terminology:
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    HTH,
    GP

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