Comparing Network States¶
Each topology you upload is a snapshot — the network frozen at the moment of capture. Topolograph keeps your snapshots over time, which means you can put two of them side by side and see exactly what changed.
The classic workflow¶
- Snapshot before. Upload the current LSDB (or let a Watcher keep snapshots flowing automatically).
- Make your change. For example, redistribute routes from BGP into OSPF with a route-map and prefix-list, adjust a link metric, or add a new adjacency.
- Snapshot after. Upload the new LSDB.
- Compare. Topolograph highlights the differences between the two states.
Because each upload is timestamped, you can compare any two points in time — not just consecutive ones.
What a comparison shows¶
- Links that appeared or disappeared between the two states.
- Cost changes on existing links.
- Networks/prefixes that were added or withdrawn.
- Nodes that joined or left the topology.
This turns "did my change do what I expected?" into a visual, verifiable answer —
instead of diffing raw show output by eye.
Pairs well with monitoring¶
Manual before/after snapshots are great for planned changes. For unplanned ones, a Watcher records every transition continuously, so you can scroll back through a timeline of states and see what changed and when — and alert on it via ELK, Zabbix or Slack.