Inter-VLAN routing issues

Routers
1

I’m banging my head with inter-VLAN communication over WiFi. It seems like all connections including at least one wired end or intra-VLAN over WiFi works like a charm, but inter-VLAN over WiFi is rather shaky. My major issue is that with my HP printer, but other unexplainable similar issues may be related. The printer is discoverable inter-VLAN over WiFi (at both ends) but it is impossible to print successfully.

I haven’t done any deeper inspection but rather looking at the symptoms while testing out pretty much every setting I have come to think of. It might be printer related to inter-VLAN communication over WiFi but it might also be a general issue, or perhaps something trivial that I am overseeing.

I have the following test setup:

Android device, OnePlus 10 Pro

  • on WiFi on VLAN 1, through AP6P → Router 10.

Windows 11 PC

  • wired on VLAN 1, through Route10, or
  • on WiFi on VLAN 1, through AP6P → Route10.

HP LaserJet M452nw printer

  • wired on VLAN 1, through Route10, or
  • on WiFi on VLAN 1, through AP6P → Route10, or
  • wired on VLAN 60, through Route10, or
  • on WiFi on VLAN 60, through AP6P → Route10.

Firewall

  • set to Allow all inter-VLAN Firewall rule as catch all in the end of the list of rules for debugging purposes.

WiFi

  • Password set to Standard.

Wired VLAN60

  • Native VLAN: 60
  • Allowed VLAN: 60 (all other unchecked)

I have narrowed it down to a few important tests to, hopefully, highlight the issue:

  1. Printer wired on VLAN 1. OK
    → Printing works for all wired and WiFi clients on VLAN 1.

  2. Printer wired on VLAN 60. OK
    → Printing works for WiFi clients on VLAN 1 (had no possibility to test PC on VLAN 1 simultaneously, as I only had an unmanaged switch at the location of the PC and printer).

  3. Printer on WiFi on VLAN 60. OK
    → Printing works from PC wired on VLAN 1.

  4. Printer on WiFi on VLAN 60. NOT ok
    → Printing does not work from Android device or PC on WiFi on VLAN 1.
    → Printer is discoverable.
    → Printer’s Web UI is reachable but works very slowly.

It may be related to issues posted here,

but I assumed that to be fixed as it was posted quite a while ago.

Also, had a look here, and moved on from IoT to Standard setting on WiFi for Printer:
https://forum.alta.inc/t/issues-connecting-epson-printer-to-wireless/2911

And here, with some similar behavior with very slow access, though still printing:
https://forum.alta.inc/t/printer-slow-connection-to-ap/2828

Is it a bug or am I missing something obvious? :thinking:

2

For your specific VLANs, how were those configured in the Settings tab?

I have a Brother printer which is wirelessly connected to VLAN 30, which I reserve for my IoT devices. I am able to print from both my wired and wireless devices that exist outside of VLAN 30. I do have mDNS enabled for my VLAN 30 and mDNS enabled for my other VLANs where I want intereaction to be supported. I know some printers will need mDNS enabled for this to work.

You could also try experimenting with IGMP Snooping and UPnP, but hopefully mDNS works for you.

3

Both VLAN 1 (devices trying to print) and VLAN 60 (printer location when issues arise) configured with IGMP Snooping and mDNS enabled. I have not yet systematically turned them On/Off in all combinations. WiFi set to IGMP Proxy enabled on WiFi associated to the respective VLANs. I might just have to try brute force try all combinations :joy: As for the UPnP-setting I interpreted that to be related to WAN traffic, which was not necessary for me, but I might have got that wrong?!

4

Update: Tried all combinations of mDNS and IGMP Snooping for my printer VLAN and also UPnP for the printer device, 2x2x2=8 combinations. All I managed to get out of it was half a paper from one of the settings. It says Printing on the printer and on the status view on the Android device, then pretty much nothing happens. After a while, say 1-2 minutes, the Android status view spits out Failed. :slightly_frowning_face:

Update2: The printer was low on black toner, and after reading up on quite a few HP forum posts it looked pretty promising that it could be the reason for slow printing turning into failed printing…BUT, unfortunately no luck there either.