Date: Wed, 26 Apr 2006 15:04:01 +0400 From: "Andrew Pantyukhin" <infofarmer@gmail.com> To: Rob <spamrefuse@yahoo.com> Cc: freebsd-questions@freebsd.org Subject: Re: How to verify speed of a 1Gb/s network? Message-ID: <cb5206420604260404u3be5bae6h2aeb4f31aec4de0a@mail.gmail.com> In-Reply-To: <20060426031606.33136.qmail@web33302.mail.mud.yahoo.com> References: <20060426031606.33136.qmail@web33302.mail.mud.yahoo.com>
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On 4/26/06, Rob <spamrefuse@yahoo.com> wrote: > Hi, > > How can I verify that a 1Gb/s network is indeed > operating at its optimal speed? I tried this: > > [master]$ ping -s 65507 node > 65515 bytes from node: icmp_seq=3D0 ttl=3D64 time=3D1.97 ms > 65515 bytes from node: icmp_seq=3D1 ttl=3D64 time=3D1.95 ms > 65515 bytes from node: icmp_seq=3D2 ttl=3D64 time=3D1.94 ms > 65515 bytes from node: icmp_seq=3D3 ttl=3D64 time=3D1.97 ms > > (I tried many times, over a long period of time > to get these typical values). > >From this I conclude that it takes about 1.95 ms > for 65515 x 8 bits to go forth and back between > master and node. > > Ideally, on a 1Gbit/s network, the time should be: > 65515 x 8 x 2 / (10243) =3D 0.98 ms > (x 2 for the roundtrip signal forth and back > and 10243 is the 1G of the network) Nopes. There's a number of 10Gig+ lines where you can't get less than 100ms, damn the light speed :-) ICMP echo service is pretty much always the lowest priority of any host. I get 2000ms+ rtt from cheap d-link devices on a gigabit network. I get 500ms+ from $10k cisco switches on any networks. Use iperf or other such tools for real testing.
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