I hadn’t done much mucking around with SNMP until connecting the apcups plugin on pfSense to my UPS. All it does is send power stats to an easy to access dashboard in the plugin. But it got me wondering about how and when to use SNMP. Towards that end, I was hoping to get some insight from those who have some experience with it.
Is SNMP just a protocol for passing statistics (like those from my UPS) across the network? Or could it be used for something cool, like managing the power settings of my network or turning devices on and off?
Or to put it more broadly, the the heck is SNMP for?
SNMP has been around a rally long time https://en.wikipedia.org/wiki/Simple_Network_Management_Protocol and how much data can be gathered from it is widely device dependent. It is up to the device creator to decided how much or how little data they shave via the protocol.
Zabbix is extensive, but does have the ability to gather SNMP information and create triggers based on that information to invoke actions.
SNMP does have a “write” functionality where you can make changes. For example, on a switch you might power cycle a POE port or change a native/access VLAN. Like reading, the options that can be written are device dependent. Also some settings that can be changed via SNMP might not be saved across reboots with the normal config - I ran into that with something LLDP related on an HPE/Aruba switch.
Where do SNMP Traps come into play? Is that just how SNMP data is received by a client?
I’m curious about SNMP because what I want is a central point to manage my entire home network. Which includes a UPS, pfSense server, FreeNAS server, XCP-ng server, switch, and wifi router. I’d like the ability to gracefully shutdown my servers if my UPS goes on battery power, power cycle servers when not in use (be it FreeNAS at night, or a VM based web server when there’s no web traffic), collect logs to a central point, and view stats on my devices. Does Zabbix fit the bill for something like that?