With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cwnManualSourceIndex
cwn Manual Source Index
1.3.6.1.4.1.9.9.223.1.3.1.1.2
An 'index' value used to identify the primary, secondary ,or default manual clock source.
Back to CISCO-WAN-NCDP-MIB MIB page.
IPHost Network monitor allows you to monitor cwnManualSourceIndex on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.