Custom MRTG Installs
Overview: The Multi Router Traffic Grapher (MRTG) is a tool to monitor the traffic load on network-links. It collects its data via SNMP traps configured on the router (network-link). SNMP allows for the monitoring of various types of data such as Fan Speed, Machine Temperature, User Logins, Network Load, and much more. This makes MRTG very flexible and allows one installation to monitor multiple "sensors" and produce data (HTML graphs) of any type of SNMP data you can collect.
Approach: When creating a new MRTG install for a client I strive to deliver a cohesive package that provides as much information as possible without overwhelming the users and at the same time provide for simple navigation. These screen shots show a custom MRTG install which monitors 1 Cisco Pix Firewall, 1 Sun Sunfire V100 Server, and 1 Sun Ultra 5 Server.
Each page includes a pull-down menu that allows the user to jump from one device to another, and each device contains as much information as seems useful for that install. Here the Pix Firewall is able to monitor bandwidth on all its interfaces and concurrent connections through the PIX itself.
Server pages include information on CPU utilization, disk space, open tcp connections, as well as bandwidth used. Since Mrtg uses SNMP to gather its information both Unix and Windows machines can be easily monitored.
Advanced MRTG installs can also include threshold monitoring, where MRTG is configured to react once a set threshold is crossed. This "reaction" can be anything as simple as an email warning sent to the System Administrator, or as complex as a custom script that will attempt to correct the issue.