Question

Your team deploys OSPF configuration changes to a batch of IOS-XE routers through a CI pipeline. Before and after each deployment, the pipeline must capture the operational OSPF neighbor state and interface state, then produce a machine-readable comparison so reviewers can confirm the change introduced no unintended side effects. You want to use pyATS CLI tools with minimal custom Python. Which approach correctly implements this change validation?

Accepted Answer

Run `pyats learn ospf interface --testbed-file testbed.yaml --output pre` before the change and `... --output post` after, then run `pyats diff pre post` to generate a structured difference report

Answer

Run `pyats validate testbed testbed.yaml` before and after the change; the command automatically compares operational state and flags any drift

Answer

Use `pyats run job` with the built-in AEtest health check, which stores CLI output as plain text and emails a unified diff to reviewers

Answer

Execute `pyats parse "show ip ospf neighbor" --testbed-file testbed.yaml` twice and rely on the parser to raise an exception when the neighbor count changes