Documentation/networking/statistics.rst

4 Interface statistics
10 This document is a guide to Linux network interface statistics.
12 There are three main sources of interface statistics in Linux:
14  - standard interface statistics based on
16  - protocol-specific statistics; and
17  - driver-defined statistics available via ethtool.
19 Standard interface statistics
22 There are multiple interfaces to reach the standard statistics.
44 Queue statistics  argument
47 Queue statistics are accessible via the netdev netlink family.
49 Currently no widely distributed CLI exists to access those statistics.
53 Protocol-specific statistics
56 Protocol-specific statistics are exposed via relevant interfaces,
62 Ethtool exposes common low-level statistics.
63 All the standard statistics are expected to be maintained
75 Standard ethtool statistics can be accessed via the interfaces used
79   $ ethtool --include-statistics -a eth0
84   Statistics:
88 General Ethernet statistics not associated with any particular
109 Driver-defined statistics
112 Driver-defined ethtool statistics can be dumped using `ethtool -S $ifc`, e.g.::
115   NIC statistics:
126 of interfaces as well as their statistics.
135 Each device directory in sysfs contains a `statistics` directory (e.g.
136 `/sys/class/net/lo/statistics/`) with files corresponding to
146 `Documentation/ABI/testing/sysfs-class-net-statistics`.
155 Statistics are reported both in the responses to link information
163 statistics.
169 specific statistics. Historically it has also been used to report
170 statistics for which other APIs did not exist, like per-device-queue
171 statistics, or standard-based statistics (e.g. RFC 2863).
173 Statistics and their string identifiers are retrieved separately.
176 to retrieve the number of statistics (`.n_stats`).
183 Protocol-related statistics can be requested in get commands by setting
185 statistics are supported in the following commands:
194 Some drivers expose extra statistics via `debugfs`.
205 Drivers should report all statistics which have a matching member in
212 Please note for example that detailed error statistics must be
216 via `/proc/net/dev`. If driver may sleep when retrieving the statistics
219 allows setting the frequency of refreshing statistics, if needed.
221 Retrieving ethtool statistics is a multi-syscall process, drivers are advised
222 to keep the number of statistics constant to avoid race conditions with
225 Statistics must persist across routine operations like bringing the interface
233 the statistics they don't report with 0.