Wireshark-users: Re: [Wireshark-users] Spanning tree can slow the network?
From: Patrick Preuss <patrick.preuss@xxxxxxxxx>
Date: Sat, 14 Jul 2012 19:58:56 +0200

You can trace on both end to See how well packets are placed time ( Maybe ntp) is Importand. So You can see where your packets are Late.

Is this only this server?

Maybe you have a problem there? Time bewegen packets go to and come from The server. 

Try to get tcp Open sequence. Most of this programms are in memory and you get neary The Network performance. Capture this on both ends best with tabs they have less impact on The enviroment.

Am Samstag, 14. Juli 2012 schrieb Andrea :
Thanks Patrick

But I don't understand why this pause occurs always on this sequence:

716    8.713191000    TCP    54    50014 > microsoft-ds [ACK] Seq=47596 Ack=55126 Win=63153 Len=0
717    9.999665000    NexcomIn_1e:63:47    Spanning-tree-(for-bridges)_00    STP    60    Conf. Root = 32768/0/00:10:f3:1e:63:45  Cost = 0  Port = 0x8003
718    10.689862000    TCP    362    [TCP segment of a reassembled PDU]
719    10.690663000    HTTP    79    HTTP/1.1 100 Continue

More than one second to receive another packet from the server ( , I think this cannot be normal behaviour.
How do I know if is normal or if it is possible optimize it?

Hi Andrea,

Spanning Tree is normal in switched networks, Bridges must send them. 

A Problem can be recalculation and reordetring of the tree.

If you what to read more about this you can read "interconnections" from radia perlmann.




Am Samstag, 14. Juli 2012 schrieb Andrea :
Hello guys,
I've captured network traffic from some customer's LAN for monitor behaviour of slow applications, in all cases I've found spanning tree packets that slow the transactions, like this:

    Spanning-tree-(for-bridge)  STP  Cost=4  port=0x8003

every time there is a spanning tree packet follow after a pause of time (about 1 sec.)  before arrives other data packets, this behaviour I've seen either in LAN with many switches and in LAN when switch was only one.

How it is possible? I don't have configure spanning tree on switches. Can this be a normal behaviour ?

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