Open source tools to help manage your Cisco network

Tools that made the short list
As I mentioned, many of these tools are advanced. Designed to fit specific needs, most of them don't fall into the category of a tool that "every Cisco administrator must have".

After perusing COSI's Web site, I came up with a list of some of the tools that I think could be particularly useful to Cisco administrators.

• ARPTrack: This Perl script maintains a history of MAC/IP pairs in a Cisco router's ARP table.
• Ciscocmd: This script sends commands to a large number of Cisco routers.
• CiscoConf: This program fetches Cisco configurations anytime syslog indicates that a router's configuration has changed. This could serve as a "poor man's system integrity verifier," similar to a very basic Rancid or Tripwire.
• cosi-ciscotool: This tool executes configuration changes on Cisco routers.
• GrotG: Also known as Gary's real-time on-demand traffic grapher, this script lets you monitor an interface (inbound, outbound, or both) in real-time.
• MRTG: Also known as Multi-Router Traffic Grapher, this tool helps monitor traffic patterns. (For more information on MRTG, check out "Configure IT Quick: Use MRTG to monitor Linux routers and firewalls.")
• RouteCheck: These Perl scripts check a router's routing table for stability.
• Show CPU load: This Perl script offers a quick look at the CPU load on a Cisco router.

While some of these tools' functionality may seem less than extraordinary at first glance, the important thing to remember with these scripts is not just what they can do by themselves but what you can do by combining their functionality with other scripts or your own scripts.

In addition, keep in mind that the benefits of such scripts often don't become evident until you have implemented several Cisco devices. When you have to individually work with every router to make a single configuration change, you'll start seeing the advantages of such automation. Possible uses

I've been working with a UNIX administrator at my company to use some of these scripts to automate Cisco IOS troubleshooting commands for a level-one support desk. We want the support desk to be able to access a menu of troubleshooting choices from a UNIX server.

For example, one of the choices might be to go to the routers and issue a show logging | inc {today's date} command to return all of the log entries for the specified day. It could then use UNIX tools such as arp and grep to parse the output further — for example, to show if the serial interface bounced that day.

Another possible use is to schedule a copy running-configuration startup-configuration and copy startup-configuration tftp to run every night. This process would save any configuration changes that occurred during the day, which could help prevent further problems if an administrator forgets to save and copy the configuration to a TFTP server.

While larger enterprise shops more than likely already have scripts and tools like these, many companies that have grown from small shops don't have such tools at their disposal. It's important to develop automated tools like these by combining the help of free Internet communities and commercial software products.