One location, two AP's. Both Omnitik U-5HnD, both running v6.18 and firmware 3.17
Both have wireless fp package installed and enabled.

Apart from their SSID and mac address and IP and access-list all other configs are the same.
All clients (mixture of old SXT, new SXT-L and rb411+R52HnP o R52nM and rb711-5HnD) are updated to 6.18 and firmware 3.17
The mix of clients devices in type is spread over the two APs
Both Omnitiks are 1,5 meter apart, different frequency. They serve to down the numbers of clients per AP (65 in total) and also serve as backup for each other.

What happens now;
Clients that are installed with the new wireless fp package, connect with no problem to Omnitik A, but not anymore to B
disable fp package and enable the normal wireless and client connect to both Omnitik again without problem.

I can repeat this drill over and over, also downgrade to 6.15 and tried that normal and fp package, result the same.

So I took a brand new SXT-L unit and configured it on my desk with a winbox transfer from a file on my PC 'drag and drop' into the winbox session to that new unit. I updated with the fp package. After reboot It connects immediately to both APs!!

So, why is one Omnitik not allowing fp package to be used on already associated CPEs?
Why is it with new CPE?

I have upgrade already 8 other AP's, whereoff 6 OmniTiks and they all don't have this issue....

Anybody any clues?

We solved the symptoms, not the issue;

we found that these 'old' CPE (old= running for a while with older software versions) were set to allow 40Mhz wide channels.
Both the AP are actually set to 20Mhz channels.
The new CPE's we configure are nowadays also set to 20mHz channels, and they have no issues connecting to both AP's.

BUT; the old ones with the 40Mhz channels option ('option' because depending on the AP) did not want to connect to one of the AP's. The other AP was ok.
So we set now all these 'old' CPE units to 20Mhz only channel width and now they connect to both AP's.

But why the 40Mhz option is now actually preventing these CPE's to get connected to one of the two almost equally configured AP's stays a mystery to us.

we found that these 'old' CPE (old= running for a while with older software versions) were set to allow 40Mhz wide channels.
Both the AP are actually set to 20Mhz channels.

This touches on an issue I've run into a few times too - not sure if it's stupidity on my part though:

How do setup a CPE that has a choice of APs to connect to but on various frequencies with different 20/40MHz extension channel positions? An example: CPE can connect to either AP 1 at 5740-Ce or AP 2 at 5840-eC. I guess from Rudy's post above that the channel configuration (eC or Ce) isn't sent by the AP to the CPE.

How do setup a CPE that has a choice of APs to connect to but on various frequencies with different 20/40MHz extension channel positions? An example: CPE can connect to either AP 1 at 5740-Ce or AP 2 at 5840-eC. I guess from Rudy's post above that the channel configuration (eC or Ce) isn't sent by the AP to the CPE.

Well, in fact the AP does communicate its setting to the CPE. Because normally if the CPE is set to Ce or eC it does connect to either Ce or eC or just 20Mhz of the AP. Its only the 10Mhz (or 5Mhz) that are not compatible in the same way. BUT;
you can now in the new software make a new list of frequencies to connect to. http://wiki.mikrotik.com/wiki/Manual:Wi ... d_Channels

In my case it is only one AP that does NOT allow CPE's that are not configured for the proper band. But this must me a error somewhere because normally it doesn't matter if CPE has eC or Ce or just 20Mhz set. It connects to whatever the AP is set to. (If other parameters are met.)

How do setup a CPE that has a choice of APs to connect to but on various frequencies with different 20/40MHz extension channel positions? An example: CPE can connect to either AP 1 at 5740-Ce or AP 2 at 5840-eC. I guess from Rudy's post above that the channel configuration (eC or Ce) isn't sent by the AP to the CPE.

Well, in fact the AP does communicate its setting to the CPE. Because normally if the CPE is set to Ce or eC it does connect to either Ce or eC or just 20Mhz of the AP. Its only the 10Mhz (or 5Mhz) that are not compatible in the same way. BUT;
you can now in the new software make a new list of frequencies to connect to. http://wiki.mikrotik.com/wiki/Manual:Wi ... d_Channels

I can see how this would work:BUT you're also saying channel-width setting is irrelevant for stations in that if AP is set to eC and CPE is set to Ce then CPE uses AP's (eC) regardless? I must test this! Interesting though...

BUT you're also saying channel-width setting is irrelevant for stations in that if AP is set to eC and CPE is set to Ce then CPE uses AP's (eC) regardless? I must test this! Interesting though...

Well yes, some settings in station or station-bridge mode are irrelevant. Like frequency setting. (Only relevant for AP modes) or this Ce or eC or just 20Mhz setting. BUT behold, it might just be this changes in next ROS version! (And actually it should. Settings that have no usage should at least be 'greyed out'.

Other setting; Data Rates. If AP has set 'default' (so 'All') and station has set some, than only these 'some' are used by station and thus AP to communicate with that station.
But if AP has set only some, and station has 'default' only the ones from the AP are used, for all. AP is 'master' so to say... station has to follow.

By the way; tnks for the karma.