Date: Tue, 03 Dec 2024 16:09:17 +0000 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: John Baldwin <jhb@FreeBSD.org> Cc: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: Re: git: b5a8abe9502e - main - How to show interface traffic in bits per second Message-ID: <202412031609.4B3G9HAf023627@critter.freebsd.dk> In-Reply-To: <a6f175eb-b81c-43be-8dba-d188eb7b40bd@FreeBSD.org> References: <202412022113.4B2LD0mt010926@gitrepo.freebsd.org> <a6f175eb-b81c-43be-8dba-d188eb7b40bd@FreeBSD.org>
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-------- John Baldwin writes: > > +When netstat reports every 8 seconds, it tells traffic in bits per se= cond: > > + > > +$ 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= : And since bytes/8 seconds =3D=3D bits/second Q.E.D > I do think having a tip about 'netstat -I foo <N>' is useful btw. I'm n= ot sure if > you are trying to do [...] I have personally used this trick for 35+ years from V.22bis modems til 10Gbit/s ethernet, to figure out how saturated a particular transmission facility is. Transmission media are always in nominal bits per second, and counters are almost invariably in bytes, so using 8 second integration eliminates the need for math. The 8 second integration time also averages most of the burstiness of the traffic quite nicely. As the author of the bikeshed email, I should have known better than to commit something this trivial :-) Poul-Henning -- = Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe = Never attribute to malice what can adequately be explained by incompetence= .
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