# why is interface speed undefined?

**URL:** <https://community.netdata.cloud/t/why-is-interface-speed-undefined/4873>\
**Category:** Help\
**Created:** [November 12, 2023, 5:24am UTC](https://community.netdata.cloud/t/why-is-interface-speed-undefined/4873 "2023-11-12T05:24:39Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![jonwaland](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.netdata.cloud/jonwaland/32/3291_2.png) [@jonwaland](https://community.netdata.cloud/u/jonwaland)\
**Post date:** [November 12, 2023, 5:24am UTC](https://community.netdata.cloud/t/why-is-interface-speed-undefined/4873/1 "2023-11-12T05:24:39Z")

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All of my ubuntu network interfaces (physical and other) are found, but the network speed is undefined:

 ![image](https://canada1.discourse-cdn.com/flex029/uploads/netdata2/original/2X/4/45bd4695a2e71084b9a5cebfea0fdb7875c4a798.png)

Do I need to configure a setting, or reset a config file?

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<div class="post-metadata">

**Author:** ![ilyam8](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.netdata.cloud/ilyam8/32/134_2.png) [@ilyam8](https://community.netdata.cloud/u/ilyam8)\
**Post date:** [November 12, 2023, 2:19pm UTC](https://community.netdata.cloud/t/why-is-interface-speed-undefined/4873/2 "2023-11-12T14:19:37Z")

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Hey, @jonwaland. Netdata gathers the speed by reading `/sys/class/net/<iface>/speed` ([sysfs-class-net](https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-net)).

> ```
> Indicates the interface latest or current speed value. Value is
> an integer representing the link speed in Mbits/sec.
> 
> Note: this attribute is only valid for interfaces that implement
> the ethtool get_link_ksettings method (mostly Ethernet).
> 
> ```

So it is undefined if `/sys/class/net/<iface>/speed` returns `-1` - ND doesn’t know the speed of the interface.

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<div class="post-metadata">

**Author:** ![jonwaland](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.netdata.cloud/jonwaland/32/3291_2.png) [@jonwaland](https://community.netdata.cloud/u/jonwaland)\
**Post date:** [November 14, 2023, 11:06pm UTC](https://community.netdata.cloud/t/why-is-interface-speed-undefined/4873/3 "2023-11-14T23:06:35Z")

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```auto
 walaj - jonlabnuc - SSH : sys / class / net / eno1 / $ uname -a
Linux jonlabnuc 5.4.0-165-generic #182-Ubuntu SMP Mon Oct 2 19:43:28 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
 walaj - jonlabnuc - SSH : sys / class / net / eno1 / $ cat speed
1000

```

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<div class="post-metadata">

**Author:** ![ilyam8](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.netdata.cloud/ilyam8/32/134_2.png) [@ilyam8](https://community.netdata.cloud/u/ilyam8)\
**Post date:** [November 15, 2023, 10:17am UTC](https://community.netdata.cloud/t/why-is-interface-speed-undefined/4873/4 "2023-11-15T10:17:48Z")

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Ok, I think I just misunderstood your question. The speed is **not undefined** , it shows the value. It is wrong and should be 1000Mbit - fixed in [16418](https://github.com/netdata/netdata/pull/16418):

 ![Screenshot 2023-11-15 at 12.12.40](https://canada1.discourse-cdn.com/flex029/uploads/netdata2/original/2X/5/5dd629565bc3d86f2d6a285d824958c66fdea58c.png)

What is undefined is the [interface\_speed alarm](https://github.com/netdata/netdata/blob/183a7fb84f85885a3d91f8e28d4e9780f964f659/health/health.d/net.conf#L7) - it just means that it has no trigger (warn, crit) conditions. That is expected, this alarm (calculated value) is used in other alarms.

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<div class="post-metadata">

**Author:** ![jonwaland](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.netdata.cloud/jonwaland/32/3291_2.png) [@jonwaland](https://community.netdata.cloud/u/jonwaland)\
**Post date:** [November 15, 2023, 11:16pm UTC](https://community.netdata.cloud/t/why-is-interface-speed-undefined/4873/5 "2023-11-15T23:16:36Z")

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Ah - my misunderstanding then - thanks!