With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cD11HtPhyFortyMHzOperationEnabled
Cisco DOT11 High-Throughput Physical Forty M Hz Operation Enabled
1.3.6.1.4.1.9.9.607.1.1.2.1.5
This object , when set to 'true', indicates that the 40 MHz Operation is enabled.
Back to CISCO-DOT11-HT-PHY-MIB MIB page.
IPHost Network monitor allows you to monitor cD11HtPhyFortyMHzOperationEnabled on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.