Static LAN communication loss

groov EPIC
1

I have a customer system with 3 EPICs, one running the strategy and the other for more IO. I will see periodic communication loss with one of the racks, that only lasts a few seconds. This will happen every few days at most, but not with any noticeable pattern. It always reconnects, but gives me minor concern that it keeps happening.

Each EPIC has their network interfaces set up for dual LAN network. Eth0 is set DHCP for connection to the internet and is physically plugged into a managed switch. Eth1 is set STATIC for a local controls network and is plugged into an unmanaged switch. Any PC that is used for accessing Groov View also has a static port plugged into the same unmanaged switch. The only fields I set up for ETH1 is the address and subnet (10.0.0.x, 255,255,255,0). The DHCP network has a 10.45.92.x subnet). A VPN is set up on each EPIC for us to use as a secure tunnel for remote support. Each PC will access Groov View via the static address.

In the strategy, each rack is configured with the static address of the EPIC, and I included the Io-Enabler chart to handle communication between the racks. My network traffic is fairly light between EPICs, I believe, as I handle IO with bulk moves to tables and convert them to variables for use in the strategy and Groov View, instead of referencing IO points directly in the strategy. One thing I noticed that I thought was strange was, when in debug mode, if I inspect one of the remote IO racks, both network interfaces indicate the same gateway address, even though I did not configure one for the static interface.

Does anyone have any ideas what might be causing these momentary communication losses, or is this to be expected?

2

Just broadly speaking, Eth0 comes pre-configured for the trusted network (local controls, programming, etc.) and Eth1 is untrusted (the internet). Have you gone through the firewall rules to flip this for your setup?

3

Yes I did. I intentionally switched the function of the ports to utilize the GetControlEngineAddress() function in PacControl for display in Groov View. We run an isolated static network for all the HMI pcs and controllers, but mobile devices will be accessing it from the DHCP network. Some of our customers networks don’t handle hostname resolution very well. In those cases I’ll display the IP address from the controller on Groov View so they can easily see what address they need for mobile access.