[Gllug] Observed speed of gigabit ethernet only about 1/4 or 1/5 of advertised

[Peter Childs]

On 23/07/07, Richard Jones <rich at annexia.org> wrote:
>
> On Mon, Jul 23, 2007 at 11:54:08AM +0100, Pete Ryland wrote:
> > On 14/07/07, Richard Jones <rich at annexia.org> wrote:
> > > Hi, I've just got a new gigabit ethernet switch to replace my ancient
> > > 10 Mbps home switch.  The old switch easily maxed out at 10 Mbps.
> >
> > No-one else mentioned it, but check that the cables you're using are
> > rated for GigE use.  I'd have to check, but I think that means minimum
> > cat5e (not just cat5) or cat6.
>
> I don't have the cables in front of me right now to check, but they
> are short patch cables and are probably basic cat5.  My question
> though: surely if they were operating in a degraded mode they'd fall
> back to 100 Mbps, rather than the ~200 Mbps observed?
>
> Rich.
>
> --
> Richard Jones
> Red Hat
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Depends weather the network cards/switch is working in degraded mode or if
your just losing packets and they are needing to be resent.

Try

sudo ping -f -c 1000 othermachine

and see if you get any packet loss, you may need to up the 1000 to get any
real data....
Bad cables may mean packet loss without the equipment working in degraded
mode.....
You want the results as close to 0 as possible.

Peter.
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