I use the dashboard. It monitors up/down/lack of connectivity to the "Internet". It doesn't monitor CRC errors, duplex errors, etc.
MX has netflow support but I'm not sure it does what you need. More info:
Have you checked the supported SNMP OID's to see if they do what you need?
I know that the IF-MIB supported by the MX (when polling it on the device itsself, not the dashboard) can report on metrics of interfaces:
Hi asked the same questions myself! Netflow doesn't work properly with some of the typical monitoring apps out there like SolarWinds which we used where I worked. Was told Stealthwatch did see the Meraki netflow format properly however its not what we wanted. So decided SNMP monitoring via PRTG is what I am trying to get to monitor the WAN interface port to get capacity used. Meraki do a very poor Job here... netflow that doesn't work and no reporting on the WAN port usage ( why not Meraki crazy ! ) In my experience ISP's aren't great at giving this data either so like me your struggling to find a decent way to show this information which is surely something most Meraki clients want to see. What is my WAN port usage !
We are using Nagios (snmp) works well. We are trying to use Solarwinds for Netflow and Syslogging, but have run into a source issue from the MX:
So I am experiencing a similar issue with Solarwinds not receiving Netflow or Syslogging, Through packet captures thou it appears that if you have multiple vlans configured the MX is not using the native vlan as the source. Once i removed all other vlans from the site to site vpn, i started to see netflow traffic and syslog messages. Is there something I can do on the dashboard to correct this behavior so netflow and syslogging are being sourced from the native vlan?