@double_teepee 

It seems that has not method to get the WAN status through a script. Maybe has system log related to WAN status. And it supports syslog protocol to collect system log.

@Andone I will confess that I would love, in general terms, to get more information on the various syslog configurations that might be possible - as this would be a good option to use.

However - there should be two easier options.

1.  Provided that you can, programatically, obtain the WAN IP address - you could simply have your script ping the interface.  If the link is down, the interface will go down, and a ping will FAIL.

Additionally I am sure there are many number of pre-written pieces of code out there which can be fed a list of IP addresses and email you upon failure.

2.  The second is a little more complex to set up, as you may require some supporting code on the system running the monitor scripts.  This is to use SNMP to poll the interface status, and then report back to you when it goes DOWN.  SNMP is a UDP protocol primarily, which will be helpful to you in that programatically you get an UP/DOWN response back, not an error timeout which would occur through other methods.

These TP-Link devices are sold within their business/corporate line of devices so should support all standard methods of network management.  This is certainly the case for the pair of TP-LINK T1600G switches I own, which are several generations older than the R600.

I'm personally about to plunge for an R605vpn router now they're available.  Hopefully they've not dropped all the nice to have features just to go with the 'common denominator' option of the Omada SDN software.  I love the software, but I also want hardware which plays nice with other devices and software - such as logging to an ELK stack for example.