netgear_smart no longer collects over SNMP. SNMP_HEALTH_PROFILE states
where the switch publishes uptime (standard sysUpTime), memory (total
and free in KiB) and CPU (a text value whose five-second figure
counts); the application polls and computes (napalm-device-types
docs/STRUCTURE.md).
Interface counters now come from the 64-bit ifXTable where the switch
has it, as the application reads them for every device.
