When I tried to set data rate modes manually i get this error from some laptop clients "incompatible HT mode or rates, reject" "association not possible:does not support all basic rates(18)" .
I tried every data rate selection and basic rates without success if i choose to try default mode clients will be able to connect.
I also checked some clients laptop adapters all of them are supporting a/b/g but not n, if i force them to use g they can conntect with 54 mbps data rate when i choose default data rate setting.
Unfortuanetly they cannot connect when i set rates manual only.

I do not want to accept any B clients in my G/N network because they reduce the speed of my network.
Regardless of my selection some clients will not connect if i set rates manually any advice for the cause and solution?

maybe this page will help you:
http://wiki.mikrotik.com/wiki/Manual:In ... Rate_table

maybe you have same basic-mcs enabled which aren't supported by the client.

Thank you Uldis,

This helps a lot but i already tried theese configurations even i select default rates to every single check box checked. Problem is when i choose configured setting %3-4 percent of clients starts giving theese errors even in N mode. Is there any difference between default and configured setting with default values selected.

My goal was to disable all B rates and only accept G/N devices, maybe disable some lower g rates also.
Unfortunately there is no difference when i select configure button "some clients will drop"

if you choose option default it ignores all the settings you change changed related to the data-rates and use the values described in that webpage.
Try disabling all the Basic-MCS rates and Basic-B rates and leave only Basic-G 6mbps rate and check if all the clients will connect back.

I tried this excatly like you told me but it also failed. For example iphone 3GS unable to connect if do not choose default but iphone 4+ can connect if i set configure option no mater what i choose from supported rates table.
problem is between default and configured choices. no matter what i do if i select configured setting some clients like iphone 3Gs will not connect.
Is this a bug in routeros?

I do not want any B clients in my network, this is the only way that i can block them, since there is no G/N option in router os.
Even with i enable all B rates, clients will not connect if i use configured mode.

Can you copy out from the console such values for each case when the iphone 3gs works and doesn't work and for iphone4+ which works:
supported-rates-b
supported-rates-a/g
basic-rates-b
basic-rates-a/g
ht-supported-mcs
ht-basic-mcs

Can you copy out from the console such values for each case when the iphone 3gs works and doesn't work and for iphone4+ which works:
supported-rates-b
supported-rates-a/g
basic-rates-b
basic-rates-a/g
ht-supported-mcs
ht-basic-mcs

Hello uldis,

can you help me....how to copy out from the console such values ?

I have same issue with an HP compaq 6530b notebook PC wireless card...work only with "default" data rates.