Any ideas why printers in a separate IoT vlan from computers may sometimes be reachable and other times become unreachable? (MacOS/Peplink 20x)

General
1

Hopefully someone can shed some light on an intermittent printer connectivity I’ve been experiencing!

Short version: I have multiple printers on an IoT vlan and computers (Macs) on a separate trusted device vlan. Bonjour forwarding is enabled and configured on the Balance 20x (8.5.2). I can often connect to the printers from the Macs, and then the printers (one old, one new) intermittently stop being reachable.

Any ideas on this one?

Happy to provide additional detail upon request.

2

This sounds similar to issues I’ve been having, in which IOT devices on a VLAN are randomly unreachable. In my case, the unreachable devices are on an Ethernet port on my Balance One.

By chance are your printers also on Ethernet VLAN?

3

Mike, after submitting my post, I came to the conclusion I needed to setup one of the printers on ethernet and see if it had the same issue, so as to determine if the issue may be with the Wi-Fi network. My gut says likely not.

I also also came to the conclusion that the reason the ring doorbell, the printer, and the sonos move are falling off the network is likely the root cause, and yes, these (and many other devices) are in a vlan setup for IoT devices. Based on that, what are your thoughts, and has peplink offered any insight to you?

4

I have multiple IOT devices on a VLAN. The symptoms I was having were

  • occasionally, one of the devices was having DNS lookup failures, which seemed to be due to a problem when DNS Caching was enabled. Peplink identified a possible bug and I think they fixed it in 8.5.2. If you suspect this, you can try turning on (or off) the DNS Proxy Cache:

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  • another issue seemed to be that the Peplink was simply denying packets between two IOT devices, even though a third device could ping both of these. This seemed to be related to a combination of VLAN + Outbound Policy (I have the IOT VLAN set to use one of my two WANs). I never did figure this one out. It feels like this problem may be improved in 8.5.2, but it’s hard to be sure, as many of the IOT devices have also had firmware updates.

If I were you though, I’d start with WiFi: are your devices dropping off? Check the peplink AP controller Log which will show you when WiFi clients join and leave the network.

5

Thank you for sharing that information.

I think I have some more troubleshooting to do and agree on checking if they are dropping off the wifi. I checked one printer, and when it became unresponsive, it was still showing as an attached client to the access point (Ruckus R510). When I can find some time, I will dig in more and report back. I’ll also try and figure out why Epson’s apps can’t find the printer (whereas my desktop sees the printer via bonjour).

6

Guess: the printers are sleeping
Suggestion: when a printer is not responding, see if it is usable from a device in the IoT VLAN. Also, the issue may be with the Access Point rather than the router.
Everyone hates printers.