RANCID monitors a router's (or more generally a device's) configuration, including software and hardware (cards, serial numbers, etc) and uses CVS (Concurrent Version System) to maintain history of changes.
RANCID does this by the very simple process summarised as:
- login to each device in the router table (router.db),
- run various commands to get the information that will be saved,
- cook the output; re-format, remove oscillating or incrementing data,
- and finally commit those changes to the revision control system