Guest WiFi gets IP/DNS but no internet through UniFi VLAN

[EssentialRug]

Hi all...having a bit of an issue moving from RM SafetyNet to Lightspeed, specifically with using Cloud DNS. 

 

For our Guest Network, we want to use Lightspeed’s Cloud DNS.

 

RM have configured a port on our router for the Guest Network and provide DHCP. They have also set the Lightspeed DNS addresses for clients connecting to this network.

 

In UniFi, we have a VLAN configured for the Guest Network. On the switch port that connects to the router, the native network is set to the default LAN, and tagged VLAN management is allowed. RM say they have configured the router port as tagged for the Guest VLAN.

 

When we connect a device directly to the router guest port via Ethernet, everything works, including Lightspeed DNS.

 

However, when connecting through WiFi, clients get the correct IP and DNS, but there is no internet access. Devices cannot ping the gateway or reach anything else.

 

Is there anything I might be missing or any additional configuration I need to check in UniFi?

Edited December 8, 2025 by EssentialRug

[AlphamaleZed]

1 hour ago, EssentialRug said:

Hi all...having a bit of an issue moving from RM SafetyNet to Lightspeed, specifically with using Cloud DNS. 

 

For our Guest Network, we want to use Lightspeed’s Cloud DNS.

 

RM have configured a port on our router for the Guest Network and provide DHCP. They have also set the Lightspeed DNS addresses for clients connecting to this network.

 

In UniFi, we have a VLAN configured for the Guest Network. On the switch port that connects to the router, the native network is set to the default LAN, and tagged VLAN management is allowed. RM say they have configured the router port as tagged for the Guest VLAN.

 

When we connect a device directly to the router guest port via Ethernet, everything works, including Lightspeed DNS.

 

However, when connecting through WiFi, clients get the correct IP and DNS, but there is no internet access. Devices cannot ping the gateway or reach anything else.

 

Is there anything I might be missing or any additional configuration I need to check in UniFi?

Have you got content filtering from unifi in place? i notice this breaks this if you have that set. spent hours trying to figure out a single issue and this was the cause lol!

turn it off and should fix it hopefully. It will be worth checking the DNS options under the VLAN too.

 

also, for my guest wifi i just use unifi content filter as i pay for the cloudflare protection so done all sections, you might want to check if this may be a better option for you.

 

 

 

[EssentialRug]

16 minutes ago, AlphamaleZed said:

Have you got content filtering from unifi in place? i notice this breaks this if you have that set. spent hours trying to figure out a single issue and this was the cause lol!

turn it off and should fix it hopefully. It will be worth checking the DNS options under the VLAN too.

 

also, for my guest wifi i just use unifi content filter as i pay for the cloudflare protection so done all sections, you might want to check if this may be a better option for you.

 

 

 

 

Thanks so much for this! Nope...not using content filtering from UniFi!

Edited December 8, 2025 by EssentialRug

[AlphamaleZed]

3 minutes ago, EssentialRug said:

 

Thanks so much for this! Nope...not using content filtering from UniFi!

ah okay if not check those DNS options.

 

I would also look at not using the filtering for guest wifi, depends how much of your school is public out of hours, its alot easier!

[psydii]

Doesn't "isolate network" block inter vlan traffic when set there?

I think you want to set the isolate clients in the ssid settings to achieve what you are looking for, and remove the above setting to allow data to get through to the rm managed router.  You will need to review the best practices for Wifi Guests 

Implementing Network and Client Isolation in UniFi – Ubiquiti Help Center

UniFi Hotspots and Captive Portals – Ubiquiti Help Center

 

[EssentialRug]

4 minutes ago, psydii said:

Doesn't "isolate network" block inter vlan traffic when set there?

I think you want to set the isolate clients in the ssid settings to achieve what you are looking for, and remove the above setting to allow data to get through to the rm managed router.  You will need to review the best practices for Wifi Guests 

Implementing Network and Client Isolation in UniFi – Ubiquiti Help Center

UniFi Hotspots and Captive Portals – Ubiquiti Help Center

 

 

Not my screenshots above...but we don't have isolate network set, we do have isolate clients in the SSID settings.

[AlphamaleZed]

6 minutes ago, psydii said:

Doesn't "isolate network" block inter vlan traffic when set there?

I think you want to set the isolate clients in the ssid settings to achieve what you are looking for, and remove the above setting to allow data to get through to the rm managed router.  You will need to review the best practices for Wifi Guests 

Implementing Network and Client Isolation in UniFi – Ubiquiti Help Center

UniFi Hotspots and Captive Portals – Ubiquiti Help Center

 

Yeah blocks it thats why use set manual DNS option on network to what you need.

[EssentialRug]

Issue resolved...kind of. The captive portal was the culprit. Removed this and all clients happily connecting and getting the correct filtering now.