F5-221 TOS 5.0.176 ARP Flooding

[Chief]

I have an F5-221 with TOS 5.0.176-00227 installed that is intermittently flooding my network with ARP requests, causing all kinds of problems on my local network:

I found one reference in the forum to a similar problem related to Microsoft Active Directory, that indicated that editing /etc/nsswitch.conf might resolve the situation. That does not fix the problem in this case.

There do not appear to be any unexpected processes running. I have no active apps installed. The NAS itself seems to be running well, other than sometimes responding very slowing when accessing network shares from it.

It have over 150 devices on my network and it appears more than half of them are impacted by this ARP flooding from TerraMaster product, resulting in problems with mDNS discovery, UDP communications, some devices periodically rebooting, etc.

How can I fix this, as quickly as possible so I and my family aren't constantly fighting this problem on our network?

[powerQ]

From my point of view, This broadcast should be sent from the clients running on your windows or mac when the client searches for NAS device on local network. Check if there is such a client got wrong, and close it.

[Chief]

From my point of view, This broadcast should be sent from the clients running on your windows or mac when the client searches for NAS device on local network. Check if there is such a client got wrong, and close it.

Normally I would agree, but captures confirm that these are definitely originating from the F5-221. The "Source" data matches the NAS, and "Tell..." IP address matches the NAS.

[Chief]

No feedback on this, or anyone else seeing anything that might make you think this is happening to you?

Symptoms on a network that the F5-221 (or possibly other TM NAS models) is ARP flooding on might include:
- Smart lighting bulbs aren't responding quickly, or bulbs controlled as a group take a few seconds to synchronise.
- Networked remote controls, like Logitech Harmony, have intermittent or no control of devices like smart TVs or Roku.
- If you have lots of cloud-connected / controlled smart devices, they don't always respond well, or at all, to commands.
- Networked cameras might intermittently not connect via their apps, or might take longer than expected to bring up or scan through video.
- Repeated network scans using apps like Angry IP Scanner or Advanced IP Scanner often find far fewer that the number of devices you know are on the network, and often a fairly significantly different number of devices on each scan.

If anything is happening on your network, try disconnecting the NAS from the network, wait a couple of minutes, and see if the issues go away.
Hook the NAS to the network again, and see if the issues come back.

If that happens, you're probably experiencing this very problem.