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From: David Lang <david@lang.hm>
To: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Cc: bloat@lists.bufferbloat.net
Subject: Re: [Bloat] AQM creeping into L2 equipment
Date: Mon, 24 Mar 2014 16:16:45 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.02.1403241614130.24916@nftneq.ynat.uz> (raw)
In-Reply-To: <20140321164218.GA9261@sesse.net>

On Fri, 21 Mar 2014, Steinar H. Gunderson wrote:

> On Fri, Mar 21, 2014 at 03:39:16PM +0000, Dave Taht wrote:
>>>> Is your hardware fast enough to run tcpdump -s 128 -w whatever.cap -i
>>>> your interface during an entire rrul test without dropping packets?
>>>> (on client and server)
>> (question to list) Are there any options to tcpdump or the kernel to
>> make it more possible to capture full packet payloads (64k) without
>> loss at these speeds? tshark?
>
> You can capture tens of gigabits of traffic if you use the mmap packet ring
> stuff. Doubt tcpdump supports it, but it wouldn't be impossible to do.
>
> I'm a bit confused if a normal machine these days can't easily saturate
> gigabit (and capture it to SSD without further problems), though.

I've been able to capture gigabit traffic with fairly normal CPUs (<3GHz), the 
key I found was to bypass all tcpdump processing at capture time, just write the 
raw packets out. I had a disk array on a medium quality FC card for this, but 
did the same thing with a 3ware 955x RAID card and a handful of SATA drives.

David Lang

  parent reply	other threads:[~2014-03-24 23:16 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-18 14:52 Steinar H. Gunderson
2014-03-18 17:17 ` Dave Taht
2014-03-18 17:53   ` Steinar H. Gunderson
2014-03-19 22:22     ` Steinar H. Gunderson
2014-03-18 18:05   ` Fred Baker (fred)
2014-03-18 18:54     ` Dave Taht
2014-03-20 16:20       ` Toke Høiland-Jørgensen
2014-03-20 16:29         ` Dave Taht
2014-03-20 16:44           ` Toke Høiland-Jørgensen
2014-03-20 17:14             ` Dave Taht
2014-03-20 19:34               ` Aaron Wood
2014-03-20 20:23                 ` Dave Taht
2014-03-20 23:41                   ` Eric Dumazet
2014-03-20 23:45                     ` Steinar H. Gunderson
2014-03-20 23:54                       ` Steinar H. Gunderson
     [not found]                     ` <CAAvOmMtt1RCpBfT1MPNh-2FRhQ1GN4xYbfNPLYJwfP6CaP5vow@mail.gmail.com>
2014-03-21 15:06                       ` Eric Dumazet
     [not found]                         ` <CAAvOmMvPpmuW1chTdX86s5sQv6X_c622k8YrjW+hN8e5JV+dzA@mail.gmail.com>
2014-03-21 17:51                           ` Eric Dumazet
2014-03-21 18:08                             ` Dave Taht
2014-03-21 22:00                               ` Eric Dumazet
2014-03-21 22:13                                 ` Dave Taht
2014-03-23 19:27                                   ` Eric Dumazet
2014-03-21 13:41               ` Toke Høiland-Jørgensen
2014-03-21 15:39                 ` Dave Taht
2014-03-21 16:42                   ` Steinar H. Gunderson
2014-03-21 18:34                     ` Toke Høiland-Jørgensen
2014-03-24 23:16                     ` David Lang [this message]
2014-03-20 18:16       ` [Bloat] AQM creeping into L2 equipment / 10G not-for-profit playground at tetaneutral.net Laurent GUERBY
2014-03-18 18:57     ` [Bloat] AQM creeping into L2 equipment Dave Taht
2014-03-18 21:06       ` Steinar H. Gunderson
2014-03-19 13:11 ` Nikolay Shopik

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