Re: git: b5a8abe9502e - main - How to show interface traffic in bits per second

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Tue, 03 Dec 2024 15:41:28 UTC 
On 12/2/24 13:13, Poul-Henning Kamp wrote:
> The branch main has been updated by phk:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=b5a8abe9502e781598dc052698fe7fa5830f59ee
> 
> commit b5a8abe9502e781598dc052698fe7fa5830f59ee
> Author:     Poul-Henning Kamp <phk@FreeBSD.org>
> AuthorDate: 2024-12-02 21:12:27 +0000
> Commit:     Poul-Henning Kamp <phk@FreeBSD.org>
> CommitDate: 2024-12-02 21:12:27 +0000
> 
>      How to show interface traffic in bits per second
> ---
>   usr.bin/fortune/datfiles/freebsd-tips | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/usr.bin/fortune/datfiles/freebsd-tips b/usr.bin/fortune/datfiles/freebsd-tips
> index c0807405005e..1e9501e3a6fb 100644
> --- a/usr.bin/fortune/datfiles/freebsd-tips
> +++ b/usr.bin/fortune/datfiles/freebsd-tips
> @@ -856,3 +856,7 @@ $ fc-list ':charset=0x1F4A1'
>   $ pkg which /usr/local/share/fonts/noto/NotoColorEmoji.ttf
>   /usr/local/share/fonts/noto/NotoColorEmoji.ttf was installed by package noto-emoji-2.042
>   %
> +When netstat reports every 8 seconds, it tells traffic in bits per second:
> +
> +$ netstat -I bge0 8
> +%

Hmm, I'm pretty sure it's in bytes, and checking the code, it seems like show_stat()
in netstat/if.c just shows the raw delta in values without scaling it by 'interval',
so I think the counts are the number of bytes sent/received in 8 seconds:

> netstat -I igc0 8
             input           igc0           output
    packets  errs idrops      bytes    packets  errs      bytes colls
         61     0     0      14418          6     0        420     0
         42     0     0       8926          5     0        346     0
         43     0     0       7631          7     0        540     0
         31     0     0       4269          6     0        420     0
         20     0     0       2173          6     0        420     0
         26     0     0       3574          5     0        346     0
         32     0     0       4407          9     0        678     0
         22     0     0       2374          5     0        346     0

I do think having a tip about 'netstat -I foo <N>' is useful btw.  I'm not sure if
you are trying to do just highlight the interval feature, or if you are highlighting
that the stat is scaled by the interval rather than the raw delta (which isn't true
for netstat, but is true for some tools (e.g. vmstat uses per-second rates in
interval mode).

-- 
John Baldwin