# genie learn

Published articles for genie learn.

This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles.

## The Snapshot Machine: genie learn and diff as a Change-Validation Safety Net on CML2

DevFeed: [The Snapshot Machine: genie learn and diff as a Change-Validation Safety Net on CML2](<https://devfeed.tech/articles/the-snapshot-machine-genie-learn-and-diff-as-a-change-validation-safety-net-on-cml2-30875.md>)

Original publisher: [Read original article](<https://brent.leekley.me/blog/snapshot-machine/>)

Author: Brent Leekley

Published: 2026-06-22T00:00:00Z

Content type: tutorial

Language: en

Sources: [brent.leekley.me blog](<https://devfeed.tech/sources/brent-leekley-me-blog.md>)

Topics: [networking](<https://devfeed.tech/topics/networking.md>), [Cisco](<https://devfeed.tech/topics/cisco.md>), [Routing (disambiguation)](<https://devfeed.tech/topics/routing.md>), [Structured-data](<https://devfeed.tech/topics/structured-data.md>), [Command-line interface](<https://devfeed.tech/topics/cli.md>)

Tags: [change-validation](<https://devfeed.tech/tags/change-validation.md>), [cisco](<https://devfeed.tech/tags/cisco.md>), [cisco-modeling-labs](<https://devfeed.tech/tags/cisco-modeling-labs.md>), [cli](<https://devfeed.tech/tags/cli.md>), [cml2](<https://devfeed.tech/tags/cml2.md>), [genie](<https://devfeed.tech/tags/genie.md>), [genie-diff](<https://devfeed.tech/tags/genie-diff.md>), [genie-learn](<https://devfeed.tech/tags/genie-learn.md>), [maintenance-window](<https://devfeed.tech/tags/maintenance-window.md>), [network-automation](<https://devfeed.tech/tags/network-automation.md>), [network-testing](<https://devfeed.tech/tags/network-testing.md>), [ospf](<https://devfeed.tech/tags/ospf.md>), [pyats](<https://devfeed.tech/tags/pyats.md>), [routing-table](<https://devfeed.tech/tags/routing-table.md>), [snapshot](<https://devfeed.tech/tags/snapshot.md>), [structured](<https://devfeed.tech/tags/structured.md>), [validation](<https://devfeed.tech/tags/validation.md>)

### AI overview

This tutorial demonstrates using Cisco Modeling Labs 2 with Genie learn and diff to validate network changes. It snapshots structured operational state before and after a maintenance change, then compares the snapshots to reveal side effects that routine show commands may miss. The source summary reports that a changed OSPF cost reroutes three destinations while adjacencies remain FULL.

### Source excerpt

Snapshot a CML2 fabric with genie learn before and after a maintenance change, then genie diff the structured state. One fat-fingered OSPF cost quietly reroutes three destinations while every adjacency stays FULL. Structured before-and-after diffs catch the side effects that show commands miss.