Every couple of weeks our LAN grinds to a near-halt. Pings on the local segment time out every other attempt. When I traced things with Wireshark I see a steady flood of Spanning Tree for Bridges CTRL MAC Pauses hitting the wire.
There is one packet with a Quanta of 0, followed by another packet with a Quanta of 65535. These alternate back and forth eating up the network.
What's frustrating is that the MAC addresses for both sender and destination are the generic STP id of 01:80:C2:00:00:01. So I can't necessarily track it down to a rogue managed switch.
Would non-managed switches forward these Ethernet pauses to other devices? I'm having trouble isolating the root cause. Right now I'm checking some NIC settings on our servers and am going to turn Flow Control off on them. They are set to Generate and Respond right now. But I would think then the MAC address of the server would show up in my packet captures.
I have mostly hubs at this site, with three unmanaged switches of various makes (one Cisco, one 3Com, one SMC) but I don't see how they could be set for using STP and whatnot since they are dumbed down...