Wireshark-users: [Wireshark-users] Spanning tree can slow the network?

From: Andrea <an.celli@xxxxxxxxxx>
Date: Sat, 14 Jul 2012 19:11:01 +0200
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 ?

Thanks
Andrew