SNMP: a Secure Fit
By John N. Stewart
As an institution's network grows, support demands grow with it. Deploying network utilization and behavior tools is one of the most essential steps in the support process. These tools provide better insight into a network's reactions, usage trends, and capacity planning.
Tools in this space include Multi-Router Traffic Grapher (MRTG) and Cricket (see "Online Resources" for information about these and other tools). Both are available in the public domain, and both provide "near realtime" graphs that represent network utilization in the form of in- and outbound traffic. This information lets you make decisions that affect the efficiency and overall operational status of your network.
Background Check
The operating systems of most network devices maintain a status table. This table contains the current operating behavior of the devices' network interfaces, disk subsystems, and CPU performance. The Simple Network Management Protocol (SNMP) allows you to retrieve this information remotely. SNMP is an open standard—a flexible format for identifying components of a computing or network device, as well as for making the status of those components available via a network-based query. SNMP was originally designed as a network management enabler; the information on a device was not only available for read, but for write (many admins now disable the write feature). This capability ensures that you can toggle an interface, reset network counters, change the interface's logical name or renumber it (for example, change its IP address) via SNMP read and write information.
