With IPHost Network Monitor you can run simple snmp requests against a Netscreen device in your network.
nsVpnMonVpnType
NETSCREEN Vpn Mon Vpn Type
The type of this VPN tunnel, either a dialup or site-to-site
Back to NETSCREEN-VPN-MON-MIB MIB page.
IPHost Network monitor allows you to monitor nsVpnMonVpnType on Netscreen device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Netscreen firewalls right now.