February-15th-2018, 01:02 PM
I continue my exploration / discovery of the product. Currently looking to the "netpi-netx-ethernet-lan" image.
I was wondering how the fieldbus interfaces of the NetX behave with that firmware when it comes to connect with redundant links.
I notice that both ports act a layer 2 port, while the cifx0 interface (layer 3) is bound to them.
For the testing, I have my fieldbus controller (Wago 750-352) with 2 LAN ports, both active (no mirroring), and connected them straight to the NetPi fieldbus ethernet ports.
It looks like both connect correctly, with 1ms roundtrip delay (ping).
I disconnected one port, then see packets loss of less than 14 packets, then back to 1ms, meaning one of the device is converging at ethernet level. Reconnect / disconnect second port, same behavior , so all seams ok.
I'm currently looking at the NetHat documentation, but haven't find the explanation of the ethernet-lan firmware. Does the NetPi has loop protection mechanism or spantree protocol support?
My goal would be expose only the main LAN interface of the NetPI into my "user" LAN, while the fieldbus interfaces connect to the IO LAN directly (so isolated), without intermediate switch, reducing failure risk:
- Netpi_A LAN0 -> FB_A LAN0
- Netpi_A LAN1 -> FB_B LAN0
- Netpi_B LAN0 -> FB_A LAN1
- Netpi_B LAN1 -> FB_B LAN1
This is a simple scenario, which create a typical loop (so redundancy), but requires a loop free mechanism to work, otherwise there will be duplicated frames.
I was wondering how the fieldbus interfaces of the NetX behave with that firmware when it comes to connect with redundant links.
I notice that both ports act a layer 2 port, while the cifx0 interface (layer 3) is bound to them.
For the testing, I have my fieldbus controller (Wago 750-352) with 2 LAN ports, both active (no mirroring), and connected them straight to the NetPi fieldbus ethernet ports.
It looks like both connect correctly, with 1ms roundtrip delay (ping).
I disconnected one port, then see packets loss of less than 14 packets, then back to 1ms, meaning one of the device is converging at ethernet level. Reconnect / disconnect second port, same behavior , so all seams ok.
I'm currently looking at the NetHat documentation, but haven't find the explanation of the ethernet-lan firmware. Does the NetPi has loop protection mechanism or spantree protocol support?
My goal would be expose only the main LAN interface of the NetPI into my "user" LAN, while the fieldbus interfaces connect to the IO LAN directly (so isolated), without intermediate switch, reducing failure risk:
- Netpi_A LAN0 -> FB_A LAN0
- Netpi_A LAN1 -> FB_B LAN0
- Netpi_B LAN0 -> FB_A LAN1
- Netpi_B LAN1 -> FB_B LAN1
This is a simple scenario, which create a typical loop (so redundancy), but requires a loop free mechanism to work, otherwise there will be duplicated frames.
