Assigning VLAN to LAN port causes loss of internet connection

Greetings. Newb here. I have the new Surf SOHO, latest firmware, using a cable modem. If I assign anything other than “Any” as the VLAN for one of the LAN ports, the router loses its internet connection. I’m hoping this is user error. Does anyone have any ideas what I might be doing wrong? Thanks in advance.

  1. Please ensure you are using latest firmware version. The latest firmware version is v.6.3.3.

  2. Do you mean only the user who connected to that LAN port lost internet?

  3. Please share the screenshot below. Please let me know which LAN port you are referring to.
    3.1 Network > Network Settings
    3.2 Network > Port Settings

  1. Yes, the router is on firmware v.6.3.3 build 1068. It came preinstalled. This is the new SOHO model that was released last week.

  2. No, the router loses its internet connection from the cable modem. I get the “DNS failed health check” message on the Dashboard screen.

  3. 3.2 Network > Port Settings

Thank you for your help.

Strange that anything done to a LAN port should impact the WAN connection.
Are you sure the cable modem is plugged into the right Ethernet port?
Is there anything in the Event Log when this happens?

Enabling VLANs is a two step process and the first step is somewhat hidden and unusual.

Are you trying to isolate one LAN port into its own VLAN? BTW, I did this for a VOIP telephone adapter thats plugged into a LAN port on my Surf SOHO.

Health checking the WAN is complicated, quite a few options. If yours are a bit too aggressive, then it may be timing co-incidence. That is, the two events may not be related. Finding the best settings for the health check may take some trial and error.

Michael, thanks for the response. I have the cable modem plugged into the WAN port and the internet connection is active unless I modify settings on the Port Settings screen.

I successfully set up a VLAN and associated a wifi SSID to it. (It is for our video streaming devices.) A separate SSID for our computers goes to the Untagged LAN. Based on the Client List screen, my devices are getting assigned to the correct IP range for the SSID they are connected to, so this part of the setup appears to be working as desired.

I also have a Roku, TiVo, and desktop computer plugged directly into the router, so I want to assign a VLAN to the ports for the video streamers, but it is as if I have physically unplugged the modem from the router whenever I make a change to the Port Settings screen. If I disable the health check it thinks it is still connected to the modem, but there is no internet connection available to any devices connected physically or wirelessly.

The Event Log is not illuminating. Here is what assigning a VLAN to a port and then changing it back to default looks like, without touching anything else:

Dec 01 18:32:02 System: Changes applied
Dec 01 18:31:53 WAN: WAN connected
Dec 01 18:30:58 System: Changes applied
Dec 01 18:30:33 System: Changes applied
Dec 01 18:30:23 WAN: WAN disconnected

Thanks for the help.

TK_Liew, I just realized that you asked for a screenshot, sorry. Here is an example of what I would like to do:


:neutral_face: The reported problem is really strange.

May I know this can be replicated easily each time you changed LAN port other than “Any”? If so, please help to open ticket for us to investigate.

Thank you.

Yes, this problem is easily replicated. I have submitted the support ticket.

I created a diagnostic report, but it appears to be encrypted. I am a little nervous about sending out this file without knowing what information is in it. A certain level of paranoia is what led me to purchase this particular router, after all. :slight_smile:

Anyone know if a hard reset of the router would clear whatever is in this report? I could set up the router with the minimum configuration needed to reproduce the problem and the resulting report would probably be easier to read that way, anyway.

Thanks again.

The Diagnostic Report contents the necessary info (e.g. system logs, configuration and etc) for Peplink Technical Support to further diagnose the problem. As long as the problem can be replicated, we are fine with any configuration on the router.

Thank you.

For anyone else who stumbles across this thread and wants the solution:

This problem is specific to the MK3 model with firmware 6.3.3. The problem is fixed in the beta 7 firmware, which is available now.

Thanks for the help, everyone.

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@ekalter Have you had any additional issues long-term? I’m having the same problem on a MK3 with firmware 7. Was there anything else that you needed to do to get this working?


Found you have opened a support regarding to the issue. We will link you with Peplink local partner to assist further.

@ekalter issue is more to WAN link disconnected and reconnect when applying VLAN settings to ports while your reported issue more to no internet connection after applying the changes.

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