Analyze SNMP-monitored network devices (switches, routers, firewalls, load balancers) in Dynatrace. Three data layers: Smartscape topology (`EXT_NETWORK_DEVICE` / `EXT_NETWORK_INTERFACE` nodes, `belongs_to` and `calls` edges); `com.dynatrace.extension.network_device.*` metrics (CPU, memory, uptime, throughput, saturation, errors); and logs (SNMP traps, syslog, auto-discovery). Use to inventory devices, find down or saturated interfaces, check device CPU/memory/uptime, map topology and neighbors, detect interface errors, and investigate traps and syslog events. Trigger: "network device", "switch", "router", "firewall", "SNMP", "interface status", "interface down", "interface utilization", "link saturation", "device CPU", "device memory", "device uptime", "device neighbors", "LLDP", "CDP", "SNMP trap", "syslog". Do NOT use for network flow/traffic or top talkers (use dt-obs-network-flows), host NIC throughput (use dt-obs-hosts), or service request/latency (use dt-obs-services).