SNMP

What it does: three poll types. "System info" reads a device's system group (name, description, uptime, contact, location) — the original poll. "Interface utilization" walks the interface table and samples each interface's in/out octet counters twice a few seconds apart, then reports bps and utilization % per interface — an on-demand bandwidth snapshot without standing up a full NetFlow/monitoring platform. Interface utilization is v2c-only. "Walk" reads every OID under a root you give it — a generic bench tool for testing whether SNMP read access works at all, or for pulling a specific table by hand (e.g. 1.3.6.1.2.1.17.4.3.1.2, the BRIDGE-MIB MAC-address-to-port table — the way to trace a MAC to a switch port when you don't have a dedicated table view for it). Capped at 500 rows so an accidentally broad root doesn't flood the results.

Setup: supports both v2c (community string) and v3 (username + auth protocol/passphrase + optional privacy protocol/passphrase, for devices that require authenticated/encrypted polling) — Walk works with either, unlike Interface utilization. Picking an auth protocol of "None" with a privacy protocol set is flagged as invalid — SNMPv3 requires auth before privacy can apply.

Safe to run: yes — it reads, it doesn't write.

Reading results: system info confirms what a device says it is — cross-check the reported vendor/model against the MAC/OUI to confirm you're talking to what you think. For interface utilization, a link consistently near its rated speed is your bandwidth-exhaustion suspect; a big in/out imbalance can point at one heavy talker. For a walk, each row is an OID and its value — narrower roots return faster and read easier than walking a whole tree.