From: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
To: Jonathan Morton <chromatix99@gmail.com>
Cc: <cake@lists.bufferbloat.net>
Subject: Re: [Cake] de-natting & host fairness
Date: Wed, 28 Sep 2016 03:56:30 +0100 [thread overview]
Message-ID: <3c28ec73-36e7-dfed-fad8-1a694d4ceeca@darbyshire-bryant.me.uk> (raw)
In-Reply-To: <8425FD26-5C1F-42B5-9087-01D81E1ED7F5@gmail.com>
On 28/09/16 00:08, Jonathan Morton wrote:
>
>> On 26 Sep, 2016, at 06:20, Kevin Darbyshire-Bryant
>> <kevin@darbyshire-bryant.me.uk> wrote:
>>
>> Another github user 'tegularius' presented some beautifully crafted
>> code that did the lookups in a much neater way. Originally it too
>> had an 'ingress' lookup problem. This was worked on and I hacked
>> some conditional 'denat' options into cake & tc.
>>
>> For your 'delight' a denat cake
>> https://github.com/kdarbyshirebryant/sch_cake/tree/natoptions along
>> with a matching tc
>> https://github.com/kdarbyshirebryant/tc-adv/tree/denat
>
> As I’m now at the stage of trying to merge this, I’m going to make
> some executive design decisions:
>
> - De-NAT IPv4 packets only. I think it’s safe to assume that IPv6
> NAT will be rare, and in any case will typically preserve host
> distinctions. This eliminates switch blocks in favour of simple if
> blocks.
Agree completely. The IPv6 stuff was inherited/for completeness but
anyone doing many to one host masquerading with IPv6 really needs a slap!
>
> - Don’t bother with the distinction between src-NAT and dst-NAT
> lookups. The full lookup has to be done anyway and then masked off,
> the use-case for the limited functionality is nebulous, and all we’re
> doing is adding a lot of nasty conditional branches to the fast
> path.
I winced at every condition as it was being put in believe me! It is
horrible and I think now is a left over from when I was trying to
understand how/why things weren't being translated as expected. I still
don't completely trust it, but that's what testing is for :-)
>
> This in turn reduces the configuration interface for the feature to a
> flag, which I’ll call “nat”.
Agreed.
Does this need to be another variable/parameter or could it be the next
bit along in the flow type?
next prev parent reply other threads:[~2016-09-28 2:56 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-26 3:20 Kevin Darbyshire-Bryant
2016-09-26 3:54 ` Dave Taht
2016-09-26 5:11 ` Dave Taht
2016-09-26 8:54 ` moeller0
2016-09-26 13:02 ` Kevin Darbyshire-Bryant
2016-09-26 13:28 ` moeller0
2016-09-26 14:06 ` Kevin Darbyshire-Bryant
2016-09-26 14:30 ` Jonathan Morton
2016-09-26 15:23 ` moeller0
2016-09-27 1:52 ` Noah Causin
2016-09-27 2:32 ` Kevin Darbyshire-Bryant
2016-09-27 4:20 ` Noah Causin
2016-09-27 14:52 ` Noah Causin
2016-09-27 15:28 ` Kevin Darbyshire-Bryant
2016-09-27 20:40 ` Noah Causin
2016-09-27 20:44 ` Jonathan Morton
[not found] ` <CAA93jw6rPE8aAGEiqf7jp3hc1J0ThrVer8PFmFLPBqANdtEixg@mail.gmail.com>
2016-09-27 20:58 ` Noah Causin
2016-09-28 4:38 ` Kevin Darbyshire-Bryant
2016-09-28 5:08 ` Noah Causin
2016-09-27 23:08 ` Jonathan Morton
2016-09-28 2:56 ` Kevin Darbyshire-Bryant [this message]
2016-09-28 3:06 ` Jonathan Morton
2016-09-28 3:33 ` Kevin Darbyshire-Bryant
2016-09-28 3:49 ` Jonathan Morton
2016-09-28 6:07 ` Kevin Darbyshire-Bryant
2016-09-28 11:08 ` Kevin Darbyshire-Bryant
2016-09-28 11:49 ` Dave Taht
2016-09-28 14:11 ` Kevin Darbyshire-Bryant
2016-09-28 5:56 ` Sebastian Moeller
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