windows_exporter/internal/collector/net/AGENTS.md

net collector

The collector reads the Network Interface PDH object with pdh.CounterTypeRaw. The object exists on every Windows host; no role is needed. It is multi-instance. These notes were recorded on a Windows Server 2025 (build 26100) Hyper-V guest that also runs the Hyper-V role.

• Instances are adapter descriptions with (, ), #, / and \ replaced by [, ], _, _ and _. The collector applies the same replacement to the adapter description for the nic label of the info metrics. There is no _Total instance.
• On this host Network Interface had only one instance, Microsoft Hyper-V Network Adapter, although Get-NetAdapter also listed the Hyper-V switch adapters Hyper-V Virtual Ethernet Adapter and Hyper-V Virtual Ethernet Adapter #2. Those appear only in the Network Adapter object (as Hyper-V Virtual Ethernet Adapter _2 for the second one), which the collector does not read.
• Current Bandwidth is in bits per second per the help text; the raw value was 10000000000 for a 10 Gbps link. The collector divides it by 8 for current_bandwidth_bytes.
• Output Queue Length is a gauge. The help text says it is always 0 because NDIS queues the requests.
• The Packets ... Discarded, Packets ... Errors and Packets Received Unknown counters are PERF_COUNTER_LARGE_RAWCOUNT but cumulative counts of packets. All were 0 here.
• The /sec counters are PERF_COUNTER_BULK_COUNT, cumulative since the adapter started. Bytes Total/sec is the sum of Bytes Received/sec and Bytes Sent/sec, and Packets/sec is the sum of Packets Received/sec and Packets Sent/sec (exact in the sample).

Counter reference

Recorded on Windows Server 2025 (build 26100). Raw and Base are the first and second values that pdh.CounterTypeRaw returns for the sample instance.

Network Interface

Multi-instance. Instances: Microsoft Hyper-V Network Adapter. Sample instance: Microsoft Hyper-V Network Adapter.

Counters the collector reads:

Counter	Type	Raw	Base
Bytes Received/sec	PERF_COUNTER_BULK_COUNT	6363880254
Bytes Sent/sec	PERF_COUNTER_BULK_COUNT	82374607
Bytes Total/sec	PERF_COUNTER_BULK_COUNT	6446254861
Current Bandwidth	PERF_COUNTER_LARGE_RAWCOUNT	10000000000
Output Queue Length	PERF_COUNTER_LARGE_RAWCOUNT	0
Packets Outbound Discarded	PERF_COUNTER_LARGE_RAWCOUNT	0
Packets Outbound Errors	PERF_COUNTER_LARGE_RAWCOUNT	0
Packets Received Discarded	PERF_COUNTER_LARGE_RAWCOUNT	0
Packets Received Errors	PERF_COUNTER_LARGE_RAWCOUNT	0
Packets Received Unknown	PERF_COUNTER_LARGE_RAWCOUNT	0
Packets Received/sec	PERF_COUNTER_BULK_COUNT	4526889
Packets Sent/sec	PERF_COUNTER_BULK_COUNT	538207
Packets/sec	PERF_COUNTER_BULK_COUNT	5065096

Not read by the collector:

• PERF_COUNTER_BULK_COUNT: Packets Received Non-Unicast/sec, Packets Received Unicast/sec, Packets Sent Non-Unicast/sec, Packets Sent Unicast/sec, TCP RSC Coalesced Packets/sec, TCP RSC Exceptions/sec
• PERF_COUNTER_LARGE_RAWCOUNT: Offloaded Connections, TCP Active RSC Connections, TCP RSC Average Packet Size