With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
alActiveSessionSubEntryUdpPort
ALTIGA Active Session Sub Entry Udp Port
1.3.6.1.4.1.3076.2.1.2.17.6.1.23
The UDP destination port used by IPSec for this connection to permit access through a firewall.
Back to ALTIGA-SESSION-STATS-MIB MIB page.
IPHost Network monitor allows you to monitor alActiveSessionSubEntryUdpPort 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.