How to enable missing SNMP on Airport Express and monitoring via LibreNMS

Apple in it’s infinite wisdom decided years back that no-one uses SNMP and then removed the SNMP configuration settings from their AirPort Utility. This is problematic for people needing to change their SNMP settings or for others who want to enable SNMP, but are running the latest Airport Express firmware. This guide should work on all Airport devices where SNMP functionality existed, but there might be firmware versions where SNMP processes have been completely removed – this is not the case on my 2nd generation Airport Express:

Since I recently installed LibreNMS, I wanted to also get the additional insight into my Airport Express WiFi. To get your SNMP configuration back, this is possible via a quick work-around:

1) Download the Windows version of the Airport Utility

2) Start the Airport Utility and Click on “Manual Setup”

3) Enable SNMP, adjust the Community String

4) Click “Update”

Once the Airport Express restarts, you can verify on your Mac if SNMP is accessible:

snmpwalk -v2c -c public YOUR-AIRPORT-EXPRESS-IP

This will produce SNMP data like the one below:

A few minutes later, LibreNMS will also successfully auto-discover your Airport Express and capture bandwidth data and diagnostics:

I then compared the exported Windows configuration file produced by Airport Utility 5.6.1 with the configuration file of OS X Airport Utility 6.3.7, but could not find the exact settings. I was able to determine that the SNMP community string is set via:

	<key>syPR</key>
	<string>public</string>

This setting is however removed when exporting from Airport Utility 6.3.7 and SNMP is most likely disabled again when you update your Airport via the 6.3.7 utility. It seems to be perfectly fine to use the Windows Airport Utility 5.6.1 to manage the Airport Express and I would think the same applies to other Airport devices where SNMP is required.