Hey @peeple,

Unfortunately this almost certainly a result of your network switch not being able to pass along the VLAN packets for the guest network. You will need to make sure that your switch supports passing tagged packets for VLANS. It is usually a commonly added feature for unmanaged switches, but it would cause the exact behavior that you are seeing.

  @peeple,

Let me talk with my team, and I will get back to you regarding the specific compatibility. It is really rare that we would see an unmanaged switch without the feature for this reason. In fact, across my over two years - this is only the second case of this I have possibly seen. It may be that your Eero setup did not isolate devices or used a different technique to segment the network.

What was the model of your switch so our team can take a look at the specs and confirm that this is in fact the cause. 

  @peeple,

Thanks! Before I go through this with my team, I would recommend going into your switch's interface and disabling the Loopback Detection feature for the port on the Deco. When the Deco switches backhaul methods, it is possible for a short network loop to be detected - which can result in your switch shutting the port down, even though the loop is harmless and only exists for a moment.

Based on the number of ports and its features, we suspect this to have some sort of web configuration interface. Do you know if you are able to manually tag ports or assign VLANS?

How to extend guest network when there is a switch between Decos

  @peeple,

I am still looking to see if there is another solution or if something else may be happening, but if it is truly unmanaged, then there is a behavior in the switch that is preventing the VLAN tagged packets from being forwarded through the switch. Unfortunately, there is not much that can be done from a Deco's perspective as it simply passes the packets with the correctly tagged VLAN - at which point it sounds like these packets are either blocked at the switch or completely stripped of their vlan data and tossed aside.

Essentially, the Decos just tag the guest network packets with a VLAN ID, which is forwarded around the network.

In your Deco Interface for the Guest Network do you see the option below to configure the VLAN ID? The footnote indicates that this option should only appear if you are using a managed switch. If it does appear, you may consider assigning another VLAN in case this vlan is already in use or reserved for a different purpose on the switch.

From the FAQ: Case 2. If you have a managed switch.

2. When you wire the satellite Deco unit to the main Deco unit through a managed switch, you may find that you cannot have access to Internet via the guest network of the satellite unit. Here we will teach you how to do the configuration on your managed switch so that the problem can be solved.

1) The main network and the guest network are separated by VLAN. The guest network is tagged with VLAN ID 591 by default, while the main network is untagged. You can also customize the VLAN ID as between 3-1024. Here we take VLAN ID 591 as an example.

Note: The VLAN ID button will only show up when your Decos are wired together through a network switch.

  @peeple 

Hi, Thank you very much for the feedback.

I saw similar feedback on other models before but not on the Deco X55 Pro yet.

https://community.tp-link.com/en/home/forum/topic/666722

Can you send an email to the technical support-https://www.tp-link.com/us/support/contact-technical-support/? Maybe the engineer could help us find a workaround.

Wait for your reply and best regards.