Design¶

Read only by construction¶

The transport offers get and walk, nothing else. There is no SET request anywhere in the library, so no bug and no caller can change a switch through it.

Standard MIBs, mirrored¶

Each getter reads one MIB group, and each model mirrors its table: field names are the MIB objects in snake_case without the table prefix, units are the MIB's. Interpretation that combines tables or switches (trunks, uplinks, device locations) lives in helpers, so a reader can always see what the switch said and what was derived.

Targeted reads¶

Getters walk whole tables in one GETBULK sequence each (GETNEXT on SNMPv1), with MIB lookups off, so requests do not resolve names. The engine loads pysnmp's MIB modules once, in create_engine(), outside the event loop. Only the standard subtrees are read; vendor trees can be huge.

Parsers never raise¶

Values of the wrong type or with unexpected indexes become None or are skipped. Property-based tests feed random answers to every getter and helper.

Privacy¶

Test data are recordings of real switches, anonymized by an allowlist script: MAC addresses become locally administered 02:00:00:00:xx:xx, IP addresses documentation addresses, names and descriptions placeholders. A test fails on any address that may be real, in the files and in unpublished commits.