There was a following problem. We have смм micro and to it are connected 4 APs. Managements over AP is in 1 VLAN. 3 APs work normally, one of АР has ceased to work, ping on it do not pass. From MIB СММ following errors are visible:
RxAlignmentErrors 14
RxFCSErrors 33
RxSymbolError-145
Anybody can tell me in what a problem?