Community discussions

MikroTik App
 
ros44
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 74
Joined: Sun Feb 25, 2018 2:05 am
Location: Sofia, Bulgaria

Client can connect to 5GHz only after disabling 802.11ac

Wed Sep 22, 2021 12:25 am

A Dell notebook with Intel AC 8265 can connect to a new hAP ac3 only if I disable the 802.11ac in the Windows driver settings of the WiFi adapter.

Can you give me any directions how to debug this issue?

---

I just replaced an existing $15 TP-Link router with a hAP ac³ device. I've used the the Quick Set -> Home AP Dual configuration. Immediately after launching it I've found a Dell Laptop with Intel AC 8265 WiFi adapter being unable to connect to the network (same SSID and password). After an hour of tests I found out that the laptop cannot connect to the 5GHz interface. If I disable the 5GHz interface, then the laptop connects immediately to the 2.4GHz interface in a second.

At first I thought it is the laptop and the WiFi adapter or the driver. So I've updated the driver of the WiFI adapter to the latest possible version from 2012. This didn't solve the problem. After playing enough with the settings of the adapter provided, I've found an option that I can switch so that the adapter works on 802.11n and not on 802.11ac. Putting the adapter to work on 802.11n seems to solve the problem. I thought that the issue is with the laptop, the driver or the WiFI adapter.

But few hours later another laptop arrived at the office (Asus) and started acting the same way - the laptop is unable to connect to the 5GHz network. This time I completely disabled the 5GHz interface until I solve the issue. After disabling the 5GHz the Asus computer also managed to connect to the network (obviously using 2.4GHz).

I have no idea hot to debug this issue. But it seems there is something wrong in the router or the configuraiton.

Can you give me any directions or hints on how to understand the reason of the problem?
 
User avatar
rextended
Forum Guru
Forum Guru
Posts: 11967
Joined: Tue Feb 25, 2014 12:49 pm
Location: Italy
Contact:

Re: Client can connect to 5GHz only after disabling 802.11ac

Wed Sep 22, 2021 1:05 am

Stop writing novels and post the config.
/export hide-sensitive file=hapac3
censore sensible part inside (true public IP, email, etc.) before put on forum.
do not delete anything, only censore when needed.
 
User avatar
mkx
Forum Guru
Forum Guru
Posts: 11381
Joined: Thu Mar 03, 2016 10:23 pm

Re: Client can connect to 5GHz only after disabling 802.11ac

Wed Sep 22, 2021 12:19 pm

While you're preparing configuration export as per instructions by @rextended, you might want to check how is property band of wireless interface set ... for maximum compatibility and flexibility it should be set to 5ghz-a/n/ac ... or if you don't have legacy 5GHz wireless clients, it can be set to 5ghz-n/ac. To experiment if things change, you can set it to 5ghz-onlyn but I advise against making this permanent setting as it degrades capability of AP.
 
biomesh
Long time Member
Long time Member
Posts: 561
Joined: Fri Feb 10, 2012 8:25 pm

Re: Client can connect to 5GHz only after disabling 802.11ac

Wed Sep 22, 2021 2:09 pm

Just a guess since there is no export, but the channels could be set to Auto and it's using a dfs channel. Some devices won't even attempt to look at anything in the dfs range.
 
User avatar
rextended
Forum Guru
Forum Guru
Posts: 11967
Joined: Tue Feb 25, 2014 12:49 pm
Location: Italy
Contact:

Re: Client can connect to 5GHz only after disabling 802.11ac

Wed Sep 22, 2021 2:32 pm

Is a guessing game
 
User avatar
bpwl
Forum Guru
Forum Guru
Posts: 2978
Joined: Mon Apr 08, 2019 1:16 am

Re: Client can connect to 5GHz only after disabling 802.11ac

Wed Sep 22, 2021 11:19 pm

OP is silent or gone....

But first step is always to check the log. (Or even make a better wifi log by adding topic "wireless" to the logging.)
Did the laptop even try to connect to 5GHz? Was it denied or any other disconnect reason mentioned in the log?
 
ros44
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 74
Joined: Sun Feb 25, 2018 2:05 am
Location: Sofia, Bulgaria

Re: Client can connect to 5GHz only after disabling 802.11ac

Thu Sep 23, 2021 11:31 am

Thank you all for taking time to reply.

At this moment I can post only this part of the configuration.
[******@******] > /interface wireless export hide-sensitive
# sep/23/2021 11:01:47 by RouterOS 6.47.10
# software id = ******
#
# model = RBD53iG-5HacD2HnD
# serial number = ******
/interface wireless
set [ find default-name=wlan1 ] band=2ghz-b/g/n channel-width=20/40mhz-XX country=bulgaria disabled=no distance=indoors frequency=auto installation=\
    indoor mac-address=EC:88:8F:****** mode=ap-bridge name=wlan1_2GHz_LAN ssid=****** wireless-protocol=802.11
set [ find default-name=wlan2 ] band=5ghz-a/n/ac channel-width=20/40/80mhz-XXXX country=bulgaria distance=indoors frequency=auto installation=indoor \
    mac-address=EC:88:8F:****** mode=ap-bridge name=wlan2_5GHz_LAN ssid=****** wireless-protocol=802.11
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa-psk,wpa2-psk mode=dynamic-keys supplicant-identity="******"
add authentication-types=wpa-psk,wpa2-psk mode=dynamic-keys name=profile supplicant-identity="******"
/interface wireless
add disabled=no mac-address=94:F6:65:****** master-interface=wlan1_2GHz_LAN name=wlan3_2GHz_GUEST security-profile=profile ssid="Guest"
add mac-address=94:F6:65:****** master-interface=wlan2_5GHz_LAN name=wlan4_5GHz_GUEST security-profile=profile ssid="Guest"

After noticing the issue I did look in the log but there was nothing there. I will add the topic "wireless" and check again.

I will check what dfs is cause I don't know yet. If dfs is different range and some devices won't even attempt to look there, I suspect they will just go to 2.4GHz range and connect.

I will also test the band property. For now what worked is to change the driver settings of one of the laptops and set it to 802.11n only.

You may notice that I did change the MAC addresses of all interfaces and also the supplicant identity. Could this be a problem?

There are two Win10 laptops behaving the same: when I click on the network name, enter the password and click Connect they try to connect and after a while they return "Can't connect to this network". I think they do try to connect to the 5GHz network because after disabling it the problem is gone. Now both 5GHz interfaces are disabled.
 
User avatar
bpwl
Forum Guru
Forum Guru
Posts: 2978
Joined: Mon Apr 08, 2019 1:16 am

Re: Client can connect to 5GHz only after disabling 802.11ac

Thu Sep 23, 2021 12:37 pm

Well .... the log should give you some information at least. "can't connect to this network" is probably at least after some attempts.

What can be wrong? ... your config is hiding the MAC addresses, important is that they are all different from each other!

You use "auto" freq selection, what I do not recommend with Mikrotik AP. You have to look in the wifi wireless status to see what freq is used.
(Tuning hint: please be careful with 40MHz channelwidth in 2.4 GHz, and 80 MHz channelwidth in 5 GHz. It may have quite some interference. 20MHz and 40 MHz is quite common in a busy environments)
(Second tuning hint: if you do not need 802.11b in the 2.4GHz band, don't enable it)


Usually what I suggest is to "forget" the stored wifi parameters for that network in the PC. (this will avoid having the wrong encryption, password and other settings remembered and used)
https://helpdeskgeek.com/networking/fix ... d-network/
Are the SSID identical between 2.4GHz and 5 GHz? For testing it might be better to have them different first.
Supplicant-identity plays no role in WPA/WPA2 AFAIK. But the passwords are important and that setting is not mentioned in this config extract. Password must be at least 8 char long for WPA2!

The client PC will disconnect often if it gets no traffic, the password is wrong or too short, gets no (DHCP) IP address, or even after a failed internet connect test...

Same problem with SSID Guest as with the other SSID ?
What if you remove /ac on the Mikrotik? (40 MHz is the max channel width for 802.11n)

But again: the log is key here in finding what's happening.
 
User avatar
rextended
Forum Guru
Forum Guru
Posts: 11967
Joined: Tue Feb 25, 2014 12:49 pm
Location: Italy
Contact:

Re: Client can connect to 5GHz only after disabling 802.11ac

Thu Sep 23, 2021 6:22 pm

From my point of view:

0: probably @bpwl is right and both SSID are the same

1st error, TP-Link MAC address on both wireless, probably the same:
set wlan1 mac-address=EC:88:8F:xx:xx:xx
set wlan2 mac-address=EC:88:8F:xx:xx:xx

2nd: enabled "b"
set wlan1 band=2ghz-b/g/n

3rd: Random Ce/eC (XX) 40Mhz (20+20) on 2GHz
set wlan1 band=2ghz-xxx channel-width=20/40mhz-XX

4th: wpa-psk is not allowed on n or ac, must be off the balls.
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa-psk,wpa2-psk
add authentication-types=wpa-psk,wpa2-psk

5th: is censored, probably the device is at least resetted once, must be "MikroTik" for default
set default supplicant-identity="******"
set profile supplicant-identity="******"

6th & 7th: Rukus MAC address on virtual interface, instead of virtual MAC for virtual interface...
probably again the same?, and again the same SSID
add mac-address=94:F6:65:****** master-interface=wlan1_2GHz_LAN name=wlan3_2GHz_GUEST security-profile=profile ssid="Guest"
add mac-address=94:F6:65:****** master-interface=wlan2_5GHz_LAN name=wlan4_5GHz_GUEST security-profile=profile ssid="Guest"
 
ros44
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 74
Joined: Sun Feb 25, 2018 2:05 am
Location: Sofia, Bulgaria

Re: Client can connect to 5GHz only after disabling 802.11ac

Tue May 03, 2022 3:28 am

7 months later I ended up repeating the problem on another location with a different router and 2 different laptops. I've found several workarounds.

The problem:
Again hAP ac3 (this time with RouterOS 7.2) with identical configuration and:
- Asus laptop with Intel Dual Band Wireless AC-8265 (again the same chip) running Win10 (again) and
- HP laptop with Intel Dual Band Wireless AC-8260 running Win10 (again).
Both laptops cannot connect to the WiFi network. Both 2.4 and 5GHz networks have the same SSID and password. Both router's wireless interfaces have spoofed mac addresses that are different.

Enabling logging with wireless,debug topic doesn't show anything.

The workarounds:
1. Stopping the 5GHz interface on the router makes the laptops connect to 2.4GHz immediately. If both interfaces are running or only 5GHz is running, then the laptops cannot connect.
2. Changing the Windows WiFi driver settings of the adapter -> Advanced -> 802.11n/ac Wireless Mode -> switching from 802.11ac to 802.11n makes the laptops connect immediately to 5Ghz.
3. Changing the Windows WiFi driver settings of the adapter -> Advanced -> Channel Width for 5GHz -> switching from Auto to 20 MHz Only makes the laptops connect immediately to 5Ghz.
4. RouterOS - Changing the Channel Width of the 5GHz interface from 20/40/80MHz XXXX to 20/40/80MHz eeeC or eeCe, eCee, Ceee makes the laptops connect immediately to 5Ghz.

I suspect there is an issue with the driver of this specific chip family. Or may be something in my configuration is making the driver confused, because phones, tablets, a ProBook, and dozen of smart devices are able to connect no matter what setting is selected.

Can you share your suggestions?
 
User avatar
mkx
Forum Guru
Forum Guru
Posts: 11381
Joined: Thu Mar 03, 2016 10:23 pm

Re: Client can connect to 5GHz only after disabling 802.11ac  [SOLVED]

Tue May 03, 2022 9:06 am

Setting frequency to auto and channel width to XXXX makes channel selection extremely non-deterministic. It does happen from time to time that ROS selects wrong centre frequency for a 80MHz channel and some clients are sensible to that. I suggest you to always configure channel width to Ceee even if keeping frequency set to auto. This way at least one of unknowns is eliminated, in addition it seems to make your troublesome clients happy.
 
ros44
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 74
Joined: Sun Feb 25, 2018 2:05 am
Location: Sofia, Bulgaria

Re: Client can connect to 5GHz only after disabling 802.11ac

Tue May 03, 2022 2:42 pm

@mkx, thank you for your clear and simple answer. I've read the forum for the eeeC or eeCe, eCee, Ceee difference.
But if you have time, can you clarify why do you recommend exactly Ceee?
 
User avatar
rextended
Forum Guru
Forum Guru
Posts: 11967
Joined: Tue Feb 25, 2014 12:49 pm
Location: Italy
Contact:

Re: Client can connect to 5GHz only after disabling 802.11ac

Tue May 03, 2022 2:45 pm

Waiting for @mkx to reply, probably is this because Ceee is the default for some devices.
 
User avatar
mkx
Forum Guru
Forum Guru
Posts: 11381
Joined: Thu Mar 03, 2016 10:23 pm

Re: Client can connect to 5GHz only after disabling 802.11ac

Tue May 03, 2022 8:47 pm

But if you have time, can you clarify why do you recommend exactly Ceee?

It comes first alphabetically :wink:
 
ros44
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 74
Joined: Sun Feb 25, 2018 2:05 am
Location: Sofia, Bulgaria

Re: Client can connect to 5GHz only after disabling 802.11ac

Tue May 03, 2022 8:53 pm

:? :lol:
 
User avatar
bpwl
Forum Guru
Forum Guru
Posts: 2978
Joined: Mon Apr 08, 2019 1:16 am

Re: Client can connect to 5GHz only after disabling 802.11ac

Tue May 03, 2022 11:33 pm

C and e use somewhat different techniques for clear-channel-assesment?
So it is best that the full bandwidth is aligned with other AP settings, and it seems to be best if they use the same C channel as well.
Primary/secondary channels and dynamic bandwidth signaling is for 80MHz wide channels only ?

See CCA chapter in https://www.oreilly.com/library/view/80 ... /ch03.html
I have no idea what of all this is implemented in MT with ac mode. (e.g. if RTS/CTS must be enabled for dynamic bandwidth or not)
 
kreload
just joined
Posts: 20
Joined: Tue Sep 15, 2020 10:18 am

Re: Client can connect to 5GHz only after disabling 802.11ac

Tue May 10, 2022 9:46 am

@mkx, thank you for your clear and simple answer. I've read the forum for the eeeC or eeCe, eCee, Ceee difference.
But if you have time, can you clarify why do you recommend exactly Ceee?
Probably because ussualy you start setting the routers from 5180 frequency and you can go in only one direction (Ceee). That doesn mean you cant select a higher freq and choose eeeC.
 
User avatar
Joni
Member Candidate
Member Candidate
Posts: 156
Joined: Fri Mar 20, 2015 2:46 pm
Contact:

Re: Client can connect to 5GHz only after disabling 802.11ac

Tue Feb 28, 2023 11:00 pm

7 months later I ended up repeating the problem on another location with a different router and 2 different laptops. I've found several workarounds.

4. RouterOS - Changing the Channel Width of the 5GHz interface from 20/40/80MHz XXXX to 20/40/80MHz eeeC or eeCe, eCee, Ceee makes the laptops connect immediately to 5Ghz.

<3 <3

Who is online

Users browsing this forum: normis and 26 guests