Hello,
Since ros version 6.30, we got an issue with station connection algorithm.
Let's say we got a station that scan 2 AP from ours:

AP1: 00:21:A4:34:05:E4
AP2: 00:21:A4:34:17:55

Both AP got the same SSID and security profile.
We want the station to connect to the AP2 as it is the closest one.
Station has done the scan process and detect network:
AP1: 00:21:A4:34:05:E4
AP2: 00:21:A4:34:17:55

Station tries to connect to AP1 as it's connect-list contains the SSID from this AP.
Connection is refuse as AP1 as no access list entry for the station.
The station should then try again few time more until it reach the max retry on a AP, then it should put it on the bottom of his network possible connection list.
But it never happens even after an hour, the station keeps trying to connect to AP1.
It keeps trying until we shutdown the AP or restart the station.
If we reboot the station, if the first AP it see is the AP1 it will try again on it forever.
AP2 got an entry in access-list for station mac address but the station never try to connect on it.

This issue is related to Ticket#2017092622001362.
For some reason, I got no answer for a month now.

Regards,
Michael Plourde
Digicom Technologies

Hello Michael,

I think you answered your own question

If I understand you:
* Station has a connect-list entry to the SSID
* Station is MikroTik device, since you use connect-list entries
* AP1 does not have access-list entry for station
* AP2 has access-list entry for station

Since AP1 refuses "station", I'll assume that "default-authenticate" is unchecked, which is OK. "Station" being refused is normal behavior at this point since AP1 has no access-list entry for "station". And you WANT "station" to go to AP2 anyway.

Since "station" is always going to AP1, I'll assume that AP1 is more interesting to "station", i.e. better signal (probably closer also).

Now, since both APs have the same SSID, how would the "station" select the good AP? Add AP2's MAC to its existing connect-list entry. As AP2 already has an access-list entry to for "station", nothing more to do there.

That should be that.

If this doesn't work, refer to the log window for meaningful messages. You may want to add "wireless" topic in logging.

Cheers,

Hello Michael,

I think you answered your own question

If I understand you:
* Station has a connect-list entry to the SSID
* Station is MikroTik device, since you use connect-list entries
* AP1 does not have access-list entry for station
* AP2 has access-list entry for station

Since AP1 refuses "station", I'll assume that "default-authenticate" is unchecked, which is OK. "Station" being refused is normal behavior at this point since AP1 has no access-list entry for "station". And you WANT "station" to go to AP2 anyway.

Since "station" is always going to AP1, I'll assume that AP1 is more interesting to "station", i.e. better signal (probably closer also).

Now, since both APs have the same SSID, how would the "station" select the good AP? Add AP2's MAC to its existing connect-list entry. As AP2 already has an access-list entry to for "station", nothing more to do there.

That should be that.

If this doesn't work, refer to the log window for meaningful messages. You may want to add "wireless" topic in logging.

Cheers,

Hi Alain,
My problem relies on the connection algorithm has station never tried to connect to AP2.
It's been 10 years we use Mikrotik for AP /CPE installation, and I can assure you that the CPE has never gone that way.
Normale behavior:

- station dress a list of acceptable APs (good protocol, supported rate, encryption, etc);
- it refers to connect list to dress a list that respect it and eliminate APs that are not matching the list;
- in a round robin way, it try to connect to APs;
- when a conenct failed X times it try the next one.

Here is the problem, it never try the next one.
Plus, I can assure you there is no logic about the signal strength in this problem, as we saw station trying to connect on AP with -88 signal strength, while another AP is closest and should give a -60 !

If you can do some test you will notice that station don't choose always the strongest signal AP first since ros > 6.28.
I am willing to let Mikrotik enter our equipment, but I don't get any answer using support ticket...

Regards,
Michael

Hello,
There is last info about the connection problem we get.
In the past ROS version, we were using a script to change channel-width every 10s to scan any AP in 5,10, 20, 20/40 Mhz channel-width.
Since channel-list has been release, we have remove the script and pull 5 differents channel-list in scan-list to get the same result we got with the script.
In the ealier routeros version that support channel-list it has worked great.
Few version after, the station were stoping try on each APs it find in the scan process, and kept trying on the same AP even if the signal were too weak or the access were deny.
After a year of debugging, it is now clear that the problem is related to great number of channel to scan before try a connection to AP.
Reducing the scan-list to 4 channel-list solved the issue and we will have to remove support for 5 mhz legacy channel-width.
Great thanks to Mikrotik support team !

The great possibility of the RouterOS is also one of his cons:
Mikrotik support team can't imaginate any configuration user will put in it.
There is a world of possibility and they have to put some limit how deep the technical support will go.
Hope it will help Mikrotik user understand that those guys works hard to give their best !

Best regards,
Michael Plourde
Digicom