What snmp OID should I watch to see if my printers and switches is up an running
bash, networking, snmp
Solution
Printers
You should use the Printer MIBv2 to monitior printer error status for jams...
- `hrPrinterDetectedErrorState` reports printer errors such as low toner, jams, etc... the RFC contains details on what specific codes mean
- `hrDeviceStatus` will reveal the big picture ability of the printer to handle tasks. For more info, see Printer MIBv2, Section 2.2.13.2
`sysUpTime.0` is an OID that reports the time a system's SNMP stack has been up (reference RFC 1213: MIB-II). If this value is returned and incrementing, it's a 99% safe bet that a printer is up. Most people use `sysUpTime` to detect whether the device has rebooted for some reason; if that happens, you'll see a sudden decrease in `sysUpTime.0`, unless your last value was around 248 days (where a 32-bit counter would roll).
Ethernet Switches
Checking the basic health of ethernet switches is usually done with checks to `sysDescr.0` or `sysUpTime.0`; the problem with this heuristic comes if you care about the up/down status of particular links... at that point, you need to check values from `ifOperStatus`, which is indexed by `ifIndex` and uses interface names from `ifName`. See the following examples...
[mpenning@Hotcoffee ~]$ ## Walk ifName correlated to ifIndex
[mpenning@Hotcoffee ~]$ snmpwalk -v 2c -c Public 172.25.116.6 .1.3.6.1.2.1.31.1.1.1.1
iso.3.6.1.2.1.31.1.1.1.1.1 = STRING: "Fa0/0"
iso.3.6.1.2.1.31.1.1.1.1.2 = STRING: "Nu0"
[mpenning@Hotcoffee ~]$ ## Walk ifOperStatus (up==1)
[mpenning@Hotcoffee ~]$ snmpwalk -v 2c -c Public 172.25.116.6 .1.3.6.1.2.1.2.2.1.8
iso.3.6.1.2.1.2.2.1.8.1 = INTEGER: 1
iso.3.6.1.2.1.2.2.1.8.2 = INTEGER: 1
[mpenning@Hotcoffee ~]$
Thus we know from the example that both interface "Fa0/0" (index: 1) and "Nu0" (index: 2) have an ifOperStatus of "up"; the index value is the last integer returned in the OID of the results.
Scripting
I assume you will use `bash` for your monitoring scripts; if so, check out Net-SNMP for your SNMP manager
Problem
I am new to snmp, and I am trying to figure out what OID's I should get/trap to see if my printers, switches (and servers) is running? I do not need to know the details - just a simple test. I have successfully med get, getbulk, (and walk) request from a device, both from bash and iReasoning MIB browser. Edit: Maybe the ``` .1.3.6.1.2.1.1.3.0 Name/OID: sysUpTime.0; Value (TimeTicks): 194 hours 43 seconds (69844352) ``` is used for just that!? What happens when something is wrong? -will this be reset immediately? -or will it just stop counting? or is it just the time since last power on?