URGENT Help Needed: The MAC address which was previously for 5GHz WLAN, currently appears in 2.4GHz WLAN and NO MAC address appears for 5GHz WLAN

[midnight.reader93]

URGENT Help Needed:

Hello, take my warm greetings and I hope you are doing well. If you have knowledge or ever faced this following issue then I really need your kind support. First, let me inform you the issue I am currently facing:

My Router Model: ASUS RT-AC66U B1
Firmware version : 3.0.0.4.386.51255 (Recently I updated to this newly released firmware and after a few days the following problem occurred)

At night time everything was alright but after I woke up in the morning found that the SSID of 5GHz WLAN is not working and also the blue LED indicator of 5GHz WLAN is also OFF. So, I did the following (one step at a time) but the same issue remained:

1) Restarted the router
2) Turned OFF both 2.4GHz & 5GHz WLAN and restarted them
3) Reset to Factory Defaults
4) Downgrade the firmware to the previous version of ASUSWRT (3.0.0.4.386.49703)
5) Changed the firmware to ASUSWRT-Merlin (RT-AC68U_386.10_0)

But the same issue remained and later I found that the MAC address which was previously for 5GHz WLAN, currently appears in 2.4GHz WLAN and NO MAC address appears for 5GHz WLAN. Also all the channels of 5GHz band appears in the user interface of 2.4GHz band and NO channel appears in the UI of 5GHz band: The 2.4GHz band showing the channel of 5GHz band (e.g. from 36 to 165) which should not be the case and also 5GHz band showing 0 channel and not broadcasting any signal (Please see the three attached screenshots for more details).

I hope you now understand the problem. Please feel free to let me know if you require any information. Thank you for your kind support and time. Take care and be happy always!

 

[Tech9]

Do hard WPS reset:

[Wireless Router] ASUS router Hard Factory Reset - Method 1 | Official Support | ASUS Global

 

[midnight.reader93]

@Tech9: Thank you so much for your promising advice. As per your instruction I have done the following procedures to accomplish "HARD RESET" as provided in your given link: https://www.asus.com/support/FAQ/1039077/

1. Turn the router off.
2. Press and hold the "WPS" button and turn the router on.
3. Power light is on (keep holding the WPS button).
4. Release the WPS button after the power LED light starts flashing.
5. Power light stops flashing and the router will automatically reboot.

After the router got rebooted the same issue remained as before: MAC address which was previously for 5GHz WLAN, currently appears in 2.4GHz WLAN and NO MAC address appears for 5GHz WLAN. Also all the channels of 5GHz band appears in the user interface of 2.4GHz band and NO channel appears in the UI of 5GHz band: The 2.4GHz band showing the channel of 5GHz band (e.g. from 36 to 165) which should not be the case and also 5GHz band showing 0 channel and not broadcasting any signal.

So could you please provide any insight? Is it possible to manually change WLAN MAC address for both 2.4GHz & 5GHz by using PuTTY with SSH connection? Please let me know your thoughts with necessary procedures. Thank you once again for your kind support. Take care and have a nice day!

 

[Tech9]

It a genuine Asus RT-AC66U B1 router or it was born as something else?

If it's a genuine Asus router - it looks like you have a failed 5GHz radio. This router has to be replaced.

 

[RMerlin]

Your symptoms are very similar to that of a failed wifi radio. You can try reviving it with an electrical reset:

1) Unplug the power while the router is still turned on
2) Wait 5-10 secs
3) Turn the router off, and plug it back in
4) Turn it on, let it boot

If after that the issue is still there, then it`s a hardware failure.

 

[midnight.reader93]

It a genuine Asus RT-AC66U B1 router or it was born as something else?

If it's a genuine Asus router - it looks like you have a failed 5GHz radio. This router has to be replaced.

Thank you once again for your nice reply. Yes, it is a genuine ASUS RT-AC66U B1 router and I used this router only for 3 years. The problem here is that the scenario of 5GHz band (e.g. channels from 36 to 165) is performing under the name of 2GHz band and those channels of 2GHz band (e.g. channels from 1 to 11) are completely disappeared. As I mentioned in my previous message that the MAC address of 5GHz band is appearing under the name of 2GHz band and that's why probably this namely 2GHz band is performing the works of 5GHz band. So the missing here is the original MAC address of 2GHz band and its related channels (e.g. channels from 1 to 11).
You might be right that I need to replace the router but I want to dive deeper to find out the issues as I used this router only for 3 years. Thank you for your invaluable time and kind support. Take care and have a wonderful moment always!

 

[ColinTaylor]

This is what happens when your 2.4GHz radio is not working any more. The GUI gets confused because it's not expecting this and puts the 5GHz settings in the 2.4GHz tab. Bottom line: It's broken.

 

[Tech9]

but I want to dive deeper

Not worth it. Upgrade to something more modern. This router is based on >10-years old technology.

 

[midnight.reader93]

Your symptoms are very similar to that of a failed wifi radio. You can try reviving it with an electrical reset:

1) Unplug the power while the router is still turned on
2) Wait 5-10 secs
3) Turn the router off, and plug it back in
4) Turn it on, let it boot

If after that the issue is still there, then it`s a hardware failure.

@RMerlin: Thank you for your nice message. For a couple times I have performed your suggested "Electrical Reset" but the issue remained as before. Let me explain once again so that you might relate this issue with other solutions if possible: The problem here is that the scenario of 5GHz band (e.g. channels from 36 to 165) is performing under the name of 2GHz band and those channels of 2GHz band (e.g. channels from 1 to 11) are completely disappeared. As I mentioned in my previous message that the MAC address of 5GHz band is appearing under the name of 2GHz band and that's why probably this namely 2GHz band is performing the works of 5GHz band. So the missing here is the original MAC address of 2GHz band and its related channels (e.g. channels from 1 to 11).
You might be right that it is hardware failure but I want to dive deeper to find out the issues as I used this router only for 3 years. Thank you for your invaluable time and kind support. Take care and have a nice day!

 

[midnight.reader93]

This is what happens when your 2.4GHz radio is not working any more. The GUI gets confused because it's not expecting this and puts the 5GHz settings in the 2.4GHz tab. Bottom line: It's broken.

Thank you so much @ColinTaylor for your valuable insight. Your explanation sounds very logical. Is there any way to fix this 2.4GHz band? Do you have any idea? Please share. Thank you.

 

[midnight.reader93]

Not worth it. Upgrade to something more modern. This router is based on >10-years old technology.

Thank you so much @Tech9. Could you please suggest me some router names and their model number to the latest technology?

 

[ColinTaylor]

Is there any way to fix this 2.4GHz band?

We've seen this problem reported before with other models. If the electrical reset didn't fix the problem then the hardware has failed so it's not repairable.

 

[Tech9]

Could you please suggest me some router names and their model number to the latest technology?

There are many threads about new router models here:

Wireless Buying Advice

Not sure which wireless router or card to buy? Ask for advice here.

www.snbforums.com

Hardware choice depends on your needs, budget and available firmware options.

 

[Tech9]

Do you have any idea?

Just to make sure - you're not restoring any saved configuration files right after the resets, correct?

 

[midnight.reader93]

We've seen this problem reported before with other models. If the electrical reset didn't fix the problem then the hardware has failed so it's not repairable.

Many many thanks @ColinTaylor for your insights. Take care and be happy always!

 

[midnight.reader93]

There are many threads about new router models here:

Wireless Buying Advice

Not sure which wireless router or card to buy? Ask for advice here.

www.snbforums.com

Hardware choice depends on your needs, budget and available firmware options.

Many many thanks @Tech9 for your valuable information. Take care and be happy always!

 

[midnight.reader93]

Just to make sure - you're not restoring any saved configuration files right after the resets, correct?

No, I didn't restore any saved configuration right after resetting. Thank you.

 

[Tech9]

To help you a bit further - if you want to stay with Asus the cheapest router I would go with is RT-AX58U or also called RT-AX3000. The most common version sold now is V2. It has no current Asuswrt-Merlin firmware support, but seems like you run stock Asuswrt anyway. The same flat design router like your RT-AC66U B1, Gigabit ports, the same firmware features, will be performance upgrade + AX support. The cheapest Asuswrt-Merlin supported router I would go with is RT-AX86S. Very popular model router around is RT-AX86U. The newest hardware version of it and the cheapest from Pro series is RT-AX86U Pro model. You have to research your local market and see what fits in your budget.

The cheapest "restore to what it was" solution is RT-AC68U router from eBay, Facebook Marketplace, etc. This model is quite reliable and safe to buy used. Your RT-AC66U B1 is the same hardware device just in flat package. Not recommended to buy in 2023, but you can have a good one for very cheap.

 

[midnight.reader93]

To help you a bit further - if you want to stay with Asus the cheapest router I would go with is RT-AX58U or also called RT-AX3000. The most common version sold now is V2. It has no current Asuswrt-Merlin firmware support, but seems like you run stock Asuswrt anyway. The same flat design router like your RT-AC66U B1, Gigabit ports, the same firmware features, will be performance upgrade + AX support. The cheapest Asuswrt-Merlin supported router I would go with is RT-AX86S. Very popular model router around is RT-AX86U. The newest hardware version of it and the cheapest from Pro series is RT-AX86U Pro model. You have to research your local market and see what fits in your budget.

The cheapest "restore to what it was" solution is RT-AC68U router from eBay, Facebook Marketplace, etc. This model is quite reliable and safe to buy used. Your RT-AC66U B1 is the same hardware device just in flat package. Not recommended to buy in 2023, but you can have a good one for very cheap.

Wow! that's such wonderful post. Thank you @Tech9 for sharing your valuable information with me. This will perfectly work for me. Besides, I will consult with you if I need upcoming future. I also regret for this inadvertent delay in responding your nice reply. But many many thanks at the end!

 

[Dangsuyngam]

URGENT Help Needed:

Hello, take my warm greetings and I hope you are doing well. If you have knowledge or ever faced this following issue then I really need your kind support. First, let me inform you the issue I am currently facing:

My Router Model: ASUS RT-AC66U B1
Firmware version : 3.0.0.4.386.51255 (Recently I updated to this newly released firmware and after a few days the following problem occurred)

At night time everything was alright but after I woke up in the morning found that the SSID of 5GHz WLAN is not working and also the blue LED indicator of 5GHz WLAN is also OFF. So, I did the following (one step at a time) but the same issue remained:

1) Restarted the router
2) Turned OFF both 2.4GHz & 5GHz WLAN and restarted them
3) Reset to Factory Defaults
4) Downgrade the firmware to the previous version of ASUSWRT (3.0.0.4.386.49703)
5) Changed the firmware to ASUSWRT-Merlin (RT-AC68U_386.10_0)

But the same issue remained and later I found that the MAC address which was previously for 5GHz WLAN, currently appears in 2.4GHz WLAN and NO MAC address appears for 5GHz WLAN. Also all the channels of 5GHz band appears in the user interface of 2.4GHz band and NO channel appears in the UI of 5GHz band: The 2.4GHz band showing the channel of 5GHz band (e.g. from 36 to 165) which should not be the case and also 5GHz band showing 0 channel and not broadcasting any signal (Please see the three attached screenshots for more details).

I hope you now understand the problem. Please feel free to let me know if you require any information. Thank you for your kind support and time. Take care and be happy always!

I'm in the same situation as you