Getting started¶

Install¶

pip install aiosnmpswitch

Python 3.12 or newer. The package depends on pysnmp 7 and cryptography (for SNMPv3 encryption).

Give the library read access¶

Create a read-only SNMP access on the switch. SNMPv3 is preferred: it authenticates every request and encrypts the answers. SNMPv1 and v2c send the community in clear text, and anyone who knows it can read the switch.

• SNMPv3: a user in a group with a read view (for example the whole tree 1.3.6.1 plus 1.0.8802 for LLDP and 1.2.840 for trunks), no write view, security level authPriv. Use the strongest protocols the switch offers; some older switches offer only SHA (SHA-1) and DES.
• SNMPv2c: a community that is not the default public, limited to the address of the program that reads it, if the switch can do that.

First read¶

import asyncio

from aiosnmpswitch import AuthProtocol, CommunityAuth, PrivProtocol, SnmpSwitch, UsmAuth


async def main() -> None:
    auth = UsmAuth("monitor", "auth-key", "priv-key", AuthProtocol.SHA, PrivProtocol.DES)
    # or: auth = CommunityAuth("my-community")
    async with await SnmpSwitch.connect("192.0.2.10", auth, timeout=5.0, retries=1) as switch:
        system = await switch.get_system()
        print(system.name, system.descr, system.up_time)


asyncio.run(main())

SnmpSwitch.connect() takes these options:

An IPv6 address uses UDP over IPv6. pysnmp imports many modules and reads its MIB files on first use, so create_engine() does both in a worker thread; the transport calls it when it gets no engine. Programs with many switches can create one engine and pass it to every switch:

from aiosnmpswitch import create_engine

engine = await create_engine()
switch = await SnmpSwitch.connect("192.0.2.10", auth, engine=engine)

Do not share one engine between switches that use the same SNMPv3 user name with different passwords: pysnmp keeps the user in the engine by name, so the switches replace each other's keys. Create one engine per set of credentials.

Credentials in your program¶

CommunityAuth and UsmAuth never show their secrets in repr(), and no error message contains them. Keep them out of command lines; the diagnostics command reads them from the environment or asks for them.