With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
c2900PortTxBroadcastFrames
Cisco 2900 Port Tx Broadcast Frames
1.3.6.1.4.1.9.9.87.1.4.2.1.9
A count of frames that are successfully transmitted and are directed to the broadcast address. Unlike RFC1573's ifOutBroadcastPkts, this object does not include those that were discarded or not sent.
Back to CISCO-C2900-MIB MIB page.
IPHost Network monitor allows you to monitor c2900PortTxBroadcastFrames on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.