Setting Port to Access and VLAN kills WiFi

Hi All,

Having a problem with a Balance 20 (running 8.1.0 Build 4939) setting LAN Port 4 to Port Type = Access and VLAN tagged. When I do the WiFi network goes down. Devices can not receive an IP address from the Peplink Balance Firewall or no routing occurs. When I set the Port Type back to Trunk and VLAN Any the WiFi works.

The weird thing is that it works on another Peplink Balance 20 in another location with no issues.

What can I check for?


What is connected to Port 4?

A Point of Sale network is connected to Port 4.

Update: I was able to set the guest WiFi network to a VLAN and it now works properly. However, the secure network will not provide devices with an IP Address from the Balance 20.


If you use Access, all traffic will be tagged on the way into the Balance 20 to the VLan that you specify. This limits the number of “networks” to just one for this physical interface. It sounds like you have a wifi access point AND the POS system connected to Port 4. Is there a switch prior to the Balance 20 that both of these devices plug into?

Your access point is most likely tagging wifi traffic with the VLan tags for each SSID, so you would need a trunk to allow that VLan traffic. If you are trying to force untagged traffic to a specific VLan, you have to use Access mode. Since a port can either be trunk or access (not both) - you will need to separate the traffic to different physical interfaces OR have a smart switch do the VLan tagging for you OR set the VLan ID on the POS network adapter (if it supports it) and use the Trunk with both VLans included.

Thanks jmjones,

The only thing connected to Port 4 is the POS network, which is using VLAN 3.
Everything else is connected via Ports 1 and 2 Untagged.
Even when Port 4 is not plugged in DHCP is not working on Ports 1/2.

And yes, I am forcing everything on Port 4 to VLAN 3 using the Access mode.


This is similar to another installation that works fine.


I don’t understand the relationship between wifi and the ethernet port (port 4). Changes to that physical interface should have no impact on the wifi - unless wifi traffic is coming in to the router on that ethernet port. What kind of wireless gear are you running and how does it connect to the Balance 20?

Since you have only said that you changed eth4 to be Access, I assume the other 3 ethernet ports are trunks. Where is your VLan tagging taking place? Is there a smart-switch somewhere in the chain that is taking untagged traffic and putting in VLan markers for the devices? I cannot explain why changing one physical interface to Access from Trunk would break DHCP on non-related physical interfaces. Maybe a bit more information about the network setup can help get you some answers.