[120027] in North American Network Operators' Group
Re: Linux shaping packet loss
daemon@ATHENA.MIT.EDU (Joe Abley)
Tue Dec 8 10:14:45 2009
From: Joe Abley <jabley@hopcount.ca>
In-Reply-To: <20091208.160135.74707586.sthaug@nethelp.no>
Date: Tue, 8 Dec 2009 15:13:48 +0000
To: sthaug@nethelp.no
X-SA-Exim-Mail-From: jabley@hopcount.ca
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 2009-12-08, at 15:01, sthaug@nethelp.no wrote:
>> Won't say I'm an expert with TC, but anytime I see packet loss on an=20=
>> interface I always check the interface itself...10% packet loss is=20
>> pretty much what you would get if there was a duplex problem. I =
always=20
>> try to hard set my interfaces on both the Linux machines and =
Switches.
>=20
> Used to set everything hard five years ago. Nowadays auto works just
> fine most of the time.
I find there is a lot of hard-coded wisdom that hard-coded speed duplex =
are the way to avoid pain.
The last time I saw anybody do a modern survey of switches, routers and =
hosts, however, it seemed like the early interop problems with autoneg =
on FE really don't exist today, and on balance there are probably more =
duplex problems caused by hard-configured ports that are poorly =
maintained in the heat of battle than there are because autoneg is =
flaky.
I've also heard people say that whatever you think about autoneg in Fast =
Ethernet, on Gigabit and 10GE interfaces it's pretty much never the =
right idea to turn autoneg off.
I am profoundly ignorant of the details of layer-2. It'd be nice to have =
more than vague rhetoric to guide me when configuring interfaces. What =
reliable guidance exists for this stuff?
Joe=
