I came upon a cool FOSS agent that supports Cisco Discovery Protocol.  Basically CDP allows Layer1/2 type information to be transmitted between devices to understand upstream/downstream connectivity.   ARP is the standards-based equivalent, but CDP has its merits, and is usually worth the extra effort.   The downside with CDP is that it is network device only (and usually on Cisco network devices); however this agent – titled cdp-tools -  allows servers to broadcast CDP information upstream to the Cisco switch/router.   The Cisco device can then be discovered by your inventory/topology engine (Monolith in my case) and stitch together a topology for display and correlation uses.

I will continue to write more posts about any new software that I run across, but feel free to reach out to us via Twitter or comments within the blog if you feel that there is anything I should look at.

Here is a  screenshot of CDP neighbors for the lab switch (hermes is the server running the CDP agent)

Screenshot of the CDP topology graph (switch2 being the CDP enabled Cisco switch)

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FOSS, cisco discovery protocol, CDP, cisco network devices, network monitoring, cool tools, network management