RSLinx - Network traffic - Flood

[stevehogg]

I have a problem that we have been dealing with for years, and I don't have the first clue how to try and fix it.

We have a few PCs that have two network cards. One is connected to the main network via DHCP and the second is connected to the PLC network via static IP. They run RSLinx Classic.

There is a main server running RSLinx gateway.

The PCs transfer data to and from various PLCs using OPC.

The issue is: If one of the computers shuts down, it seems like the network gets flooded by requests trying to "find" the disconnected PC. This causes all other network traffic (on the PLC side) to stop for what seems to be exactly 3 minutes.

Hopefully someone can help. Thanks in advance.

 

[TheWaterboy]

Have you sniffed the network? what kind traffic is flooding it? That will be important to know.

The 3 minute thing sounds like the older version of Spanning Tree protocol from a switch that is looking for the other end of the "ring" connection. But a single PC being shut down should not cause that effect unless traffic is being routed THROUGH the PC. You could check your managed switches for that setting (STP or RSTP). But if you are using it, someone should know about it.