With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
alCertStatsServerCRLRequests
ALTIGA Certificate Statistics Server CRL Requests
1.3.6.1.4.1.3076.2.1.2.27.2.1.9
The total number of CRL request packets sent to this CA since client start-up. This does not include retransmissions.
Back to ALTIGA-CERT-STATS-MIB MIB page.
IPHost Network monitor allows you to monitor alCertStatsServerCRLRequests 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.