Wednesday, July 24, 2024


The VPN Tunnel Traffic Grapher, or just simply VPNTTG, is software for SNMP monitoring and measuring the traffic load for IPsec (Site-to-Site, Remote Access) and SSL (With Client, Clientless) VPN tunnels on a Cisco Appliances. It allows the user to monitor traffic load on a VPN tunnel over time in graphical form.

How it works

VPNTTG uses the Simple Network Management Protocol (SNMP) to send requests to a device such as Cisco Firepower Threat Defense, Cisco ASA 5500 Series Adaptive Security Appliances or to similar VPN concentrator which has CISCO-IPSEC-FLOW-MONITOR-MIB and CISCO-REMOTE-ACCESS-MONITOR-MIB support. The device must be SNMP enabled. VPNTTG stores monitoring data into the SQL server and into the RRD (Round Robin Database) file for each VPN tunnel as well. VPNTTG has web based intuitive graphical user interface in order to select and/or search interesting VPN tunnel and monitor incoming/outgoing bandwidth traffic on a daily, weekly, monthly and yearly basis.

Advantage of VPNTTG over other SNMP based monitoring software’s is following: Other (commonly used) software’s are working with static OID numbers, i.e. whenever tunnel disconnects and reconnects, it gets assigned a new OID number. This means that the historical data, gathered on the connection, is lost each time. However, VPNTTG works with VPN tunnel’s IP address and it stores for each VPN tunnel historical monitoring data into the SQL server and into the RRD (Round Robin Database) file.



  • Easy installation with RPM or DEB Linux package management system.
  • Easy configuration with intuitive Web GUI.
  • Adds new VPN tunnel to the list automatically.
  • Measures two values - incoming/outgoing traffic per VPN tunnel.
  • Gets its data via an SNMP agent and simultaneously stores it into the SQL server and into the RRD (Round Robin Database) file with RRDtool - industry standard, high performance data logging and graphing system for time series data.
  • Typically collects data every minute.
  • Ability asynchronous SNMP polling of VPN devices.
  • Ability to aggregate Site-to-Site Phase 2 tunnels traffic.
  • Ability to aggregate certain user’s RA tunnels traffic.
  • Adds calculated Current, Average, Maximum, Minimum and Summary for both incoming and outgoing traffic.
  • Shows detailed information for each VPN tunnel. Namely, tunnel’s IP address, first time (time when tunnel has established its first VPN connection), last time (latest time when tunnel’s VPN tunnel was connected), VPN tunnel number, VPN tunnel status.
  • Shows summary bandwidth traffic for all VPN tunnels and active VPN tunnels’ statistics as well.
  • Event logging
  • Alerting by E-mail
  • Very fast SNMP agent (written in C)

Software Requirements

Server side


  • Any modern web browser