Guest Network Pro (IoT network)

[BeachGuy]

Merlin v3006.102.5. Main router GT-AX6000 with another GT-AX6000 in MoCA wired backhaul (2.5GbE) AiMesh mode

I set up Guest Network Pro for IoT Network. Devices that were connected @ 5GHz on "standard" network have "excellent" signal but when connected to IoT network (I guess VLAN?) they only have "fair" signal. Is that because they're "virtual"? How can I get a better signal through IoT network?

 

[bennor]

It may help if you post some readable screen shots of what you are seeing and your Guest Network Pro profile IoT configuration. Redact the sensitive information. Also include to which device your WiFi clients are connecting to, the main router or the AiMesh node.

 

[BeachGuy]

It may help if you post some readable screen shots of what you are seeing and your Guest Network Pro profile IoT configuration. Redact the sensitive information. Also include to which device your WiFi clients are connecting to, the main router or the AiMesh node.

Not sure what "readable screen shots of what you are seeing" means. Previously "seeing" excellent connection, now with IoT "seeing" fair connection. For example Roku 4K Streaming Stick is connected to standard network node with "excellent" connection but when connected to node on IoT network it shows "fair" connection.
Just standard setup of IoT network (default). It doesn't matter which device clients connect to, they have always had "excellent" signal but now have "fair" when connected to either main or node.

 

[bennor]

Not sure what "readable screen shots of what you are seeing" means.

It means just that. Post readable router GUI screen shots of your router's WiFi and Guest Network Pro IoT settings, and where you are seeing this "excellent or fair connection indication, so others can review and see what you see. Include screen shot(s) of the Wireless Log too form the router. Otherwise no one has any context without more information.

 

[BeachGuy]

It means just that. Post readable router GUI screen shots of your router's WiFi and Guest Network Pro IoT settings, and where you are seeing this "excellent or fair connection indication, so others can review and see what you see. Include screen shot(s) of the Wireless Log too form the router. Otherwise no one has any context without more information.

The "excellent/fair" connection is on the TV screen of the roku.

 

[BeachGuy]

The question is directed more to someone knowledgeable about the main network function versus VLAN function and how signals may be different or processed.

 

[bennor]

The question is directed more to someone knowledgeable about the main network function versus VLAN function and how signals may be different or processed.

Generally the wireless signal should be similar. The difference typically comes from connecting to a AiMesh Node versus connecting to the main router due to either hardware differences between AiMesh node and main router, or between different location between main router and AiMesh node. Your WiFi environment may also play a roll as you turn devices on and off. You would likely need to review what the router is indicating for the client connection (for example what the Wireless Log indicates) when you have it connected to the main LAN vs when connected to the Guest Network Pro.

The reason why it was asked for detailed information including screen shots was to see how the WiFi is configured and if anyone reading may have suggested improvements. And if you have a different configuration between main LAN and Guest Network Pro, for example having main LAN WiFi 2.4/5Ghz split but combined on the Guest Network Pro profile.

The indicators on the client device may not give the granular details needed to tell if there is a real problem/issue or just a client device that may be on the edge of good vs adequate WiFi signal that fluctuates due to WiFi environment.

 

[BeachGuy]

Generally the wireless signal should be similar. The difference typically comes from connecting to a AiMesh Node versus connecting to the main router due to either hardware differences between AiMesh node and main router, or between different location between main router and AiMesh node. Your WiFi environment may also play a roll as you turn devices on and off. You would likely need to review what the router is indicating for the client connection (for example what the Wireless Log indicates) when you have it connected to the main LAN vs when connected to the Guest Network Pro.

The reason why it was asked for detailed information including screen shots was to see how the WiFi is configured and if anyone reading may have suggested improvements.

The indicators on the client device may not give the granular details needed to tell if there is a real problem/issue or just a client device that may be on the edge of good vs adequate WiFi signal that fluctuates due to WiFi environment.

Ok thanks. I guess I'm wondering if there's something fundamentally different between main network and VLANs on ASUS routers. Especially regarding signal strength.

 

[BeachGuy]

This is what chatGPT said but my goal in posting on this forum was to get expert advice from the forum as I know AI isn't always correct. I'm not sure I can configure professional settings on VLAN. I'll have to look at some of this stuff later when family isn't on internet.

I have Merlin v3006.102.5 on GT-AX6000. I set up "Guest Network Pro - IoT Network" and noticed roku device reported "fair" signal when connected to that versus "excellent" when connected to main network.

ChatGPT said:​

Excellent observation — and yes, what you’re seeing can absolutely happen, and it’s not a coincidence.
Your setup (GT-AX6000 running ASUSWRT-Merlin 3006.102.5) uses the new Guest Network Pro (GNP) implementation, which relies on VLAN-based segmentation under the hood. The “IoT Network” you created is not just a renamed SSID — it’s an entirely separate virtual interface, with its own VLAN tag, virtual bridge (brX), and sometimes different wireless scheduling and airtime rules.
Let’s break down why your Roku reports “fair” signal on the IoT VLAN but “excellent” on the main SSID.

---

1. Different Virtual Interface Path​

When you create an IoT SSID under Guest Network Pro:

• ASUSWRT internally creates a separate virtual wireless interface, e.g.
  • Main 2.4GHz → wl0
  • IoT 2.4GHz → wl0.1
  • Main 5GHz → wl1
  • IoT 5GHz → wl1.1
• Each virtual interface has its own beacon, BSSID (MAC address), and sometimes different transmit power and airtime priority.

This means your Roku is not actually connecting to the same physical radio instance — it’s connecting to a VAP (Virtual Access Point) layered on the same hardware but possibly with:

• Lower transmit power, or
• Different QoS weighting, or
• Extra VLAN encapsulation overhead.

---

2. Guest Network Pro – IoT Mode Behavior​

Guest Network Pro is designed to isolate IoT devices for security, not optimize for throughput. It applies:

• VLAN tagging and firewall isolation (br2 or br3 instead of br0)
• Optionally disables multicast-to-unicast conversions (affects discovery)
• May disable 802.11k/v/r roaming optimizations on those VAPs
• Sometimes reduces beacon interval or transmit power slightly to prevent overlapping with main SSIDs

That last factor (slightly lower Tx power or reduced MCS rate adaptation aggressiveness) can cause devices like Roku — which rely on signal-to-noise and rate adaptation feedback — to label it as “fair” signal even though physically it’s the same antenna.

---

3. Signal Quality vs. PHY Rate​

Roku’s “signal quality” metric is derived from RSSI + SNR + PHY rate negotiation, not just power.
Because the IoT VLAN interface might:

• Use a different basic rate set
• Enforce legacy compatibility (802.11b/g/n only) on the 2.4GHz IoT SSID
• Omit beamforming or MU-MIMO flags

… the reported “signal quality” can drop even though RSSI in dBm hasn’t changed.
You can verify this by comparing the two in the router UI or SSH:

wl -i wl0.1 rssi
wl -i wl0 rssi

If RSSI is identical, it’s not signal power — it’s PHY rate differences.

---

4. How to Fix or Improve It​

If you want your IoT SSID to behave identically to your main one in radio performance but still keep VLAN isolation:

1. Use the same band and channel settings as the main SSID
   → Ensure the IoT SSID isn’t limited to 2.4GHz if your Roku supports 5GHz.
2. Enable “Smart Connect” exclusions manually
   → Sometimes Smart Connect prioritizes main SSIDs with higher airtime weight.
3. In the Wireless > Professional tab, for your IoT VAP (e.g. wl0.1 or wl1.1):
   • Disable Airtime Fairness
   • Enable Explicit Beamforming
   • Set Tx Power Adjustment = 0 dB (default)
   • Ensure Multicast rate = “Auto” (not fixed low)
4. Optionally test without VLAN isolation
   Temporarily assign the IoT SSID to br0 (main LAN bridge) to confirm it’s not radio-level — if signal returns to “excellent,” it’s a VLAN interface policy difference, not RF attenuation.

---

5. Summary​

Factor	Main SSID	IoT SSID (Guest Network Pro)	Effect
Bridge	br0	br2 / br3	Isolated VLAN
Interface	wl0 / wl1	wl0.1 / wl1.1	Separate virtual radio
Tx power	Full	Sometimes reduced
802.11k/v/r	Enabled	Often disabled
Beamforming	On	May be off
QoS/Airtime	Normal	Deprioritized
Roku Signal	Excellent	Fair

 

[RMerlin]

as I know AI isn't always correct.

And in fact, the very first paragraph from ChatGPT is wrong...

it’s an entirely separate virtual interface, with its own VLAN tag

That is incorrect. The default IoT Network shares the same default VLAN as the main network. Its only goal is to provide Wireless settings that have better compatibility with the cheap/outdated wireless junk used in many IoT devices. For example to disable WPA3.

 

[BeachGuy]

And in fact, the very first paragraph from ChatGPT is wrong...


That is incorrect. The default IoT Network shares the same default VLAN as the main network. Its only goal is to provide Wireless settings that have better compatibility with the cheap/outdated wireless junk used in many IoT devices. For example to disable WPA3.

Thanks for replying and thanks for your excellent firmware. Are there specific settings that I should configure for better signal?

 

[RMerlin]

Thanks for replying and thanks for your excellent firmware. Are there specific settings that I should configure for better signal?

The default settings are almost always the best in terms of signal/coverage. You might benefit from reducing channel width if performance is not important, but this is done globally for the whole band, not on a per network basis. The most straightforward is to ensure that the 2.4 GHz band is set to 20 MHz only, you don't want 40 MHz on that band. For 5 GHz, limit it to 80 MHz is if you were using 160 MHz, and use the lower channels like 36.

If you see that much of a difference on the IoT network versus the main network make sure you are comparing the same band (2.4 GHz versus 2.4 GHz for example). The only difference that would explain a signal difference would be 2.4 GHz vs 5 GHz.