Problem with Layer 2

Question

Hello..

I have a strange scenario that is with PLC's communicating to there endpoint destination. The switches in play are 1 x S3148, 2 x N2248, 2 x N2224.

The 3 PLC devices connected at 100mb on the switch are using Layer 2 as there is no need for routing. These devices are configured on there own VLAN 80 network, which is setup on all switches and trunks. Dell trunks speeds are 10Gb SFP+. So describing the path, PLC devices connected to an N2224, then its trunk connects to another N2224, which its trunk connects to the stacked N2248's, its trunk then connects to the S3148. From the S3148 it leaves out a 1GB SFP Trunk to another building were its endpoint resides. This all work when I had them connected to our old HP V1910 switches using Layer 2.

VLAN 80 Network: 172.16.8.0 /22

PLC 1 - 172.16.9.39, PLC 2 - 172.16.9.40 , PLC 3 - 172.16.9.41, Endpoint - 172.16.8.100

I have turned on VLAN routing for this VLAN 80 to just verify the devices are responding on network. I am able to ping these from any switch, I am able to ping the endpoint device from all the switches. I verified that the switch at the endpoint can also ping the devices at my site. Mac addressing from the devices all appear in the ARP tables.

But these devices still don't find the endpoint over the trunks.

Now to get these devices communicating until I can find a solution I have pulled cable directly to the S3148 and the PLC devices work perfectly, communicating with the endpoint. So can anyone steer me in a direction that can help as to what I am missing on these N2200 series that PLC's do not want to communicate over the trunks.

IP routing is enabled on the N series. I don't use VLAN 1.

In this network I have Wifi, VOIP, Servers, Camera's and PC's that all work fine over all these trunks and also communicate within thier Layer 2 or Layer 3 VLANs across the S3148 link. But for some reason I cannot get these PLC devices to work.

I have not placed a sniffer as that is something not easy but can be done as a last resort.

Any direction greatly appreciated.

Thanks and sorry for the long read.

DELL-Joey C · Answer

Hi @FMU021,

It sounds either would be a configuration issue or compatibility issue. Can you let us know what PLC device are you using? Do you know what protocol are the PLC devices are using? If in any case that it's configuration issue, we are unable to help check on it. It would be best to contact Dell sales and support to have someone check the configuration if it's incorrect.

Alternative, if you're looking for suggestion by the public, we may need to wait for someone who has the same issue to respond to your post.

FMU021 · Answer

Hi Joey.. Thanks for the reply. PLC is communicating over udp 47808. Open to anything to look for. Thanks

FMU021 · Answer

Do Dell N series or S3100 series switches block UDP ports by default. Is there a way I can check if that UDP port is not blocked. Thanks

DELL-Josh Cr · Answer

Hi, It shouldn’t deny them by default, but it could be part of an ACL. Page 495 https://dell.to/2XIe9tC

FMU021 · Answer

I have no ACLs in place on any of these switches at this time.

DELL-Joey C · Answer

Hi @FMU021,

I would probably suggest best to contact support to check on the configuration of the switches based on your environment requirement. Since mentioned that most of all devices connected to the network is working fine except PLC devices.

Networking General

Problem with Layer 2

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