Device Discovery On Class B Network

Matt H · ‎05-10-2016

Good Morning. I searched for this and didn't see any results so thought I'd just ask.

I have recently inherited the Collector and SNTC Portal. We have a very large multi-site network that has grown rather haphazardly over time.

In an effort to make sure I am discovering everything, it was proposed that I simply run the device discovery on entire Class B networks since that's about the only way to be sure I can hit everything at a site. The idea was to run 1 class B per night

Does anyone have any experience with doing this? My concern is over the traffic and resources that this could potentially use as well as how long it would take to run the job.

Thank you for any insight anyone might be able to share.

Lynden Price · ‎05-11-2016

Hi Matt,

A /16 can take up to 12 hours to run. Depending on how many of them you have, this could cause overlapping jobs on the collector which could create issues with running inventories or performing uploads.

A protocol based discovery is a better option for finding everything, using a protocol such as CDP. For each segment of the network, you can provide a list of "seed" IP addresses. The collector will use those as a base and crawl through the network locating other devices. This usually keeps the inventory up to date.

If you don't have CDP enabled or you think the protocol discovery will miss parts of the network (going over a VPN, etc.) then you can run /16 scans on those parts.

Thanks,

Lynden