Date: Wed, 16 Aug 2006 15:57:04 -0700 From: Julian Elischer <julian@elischer.org> To: Peter Jeremy <peterjeremy@optushome.com.au> Cc: Bachilo Dmitry <root@solink.ru>, freebsd-current@freebsd.org Subject: Re: throughput and interrupts Message-ID: <44E3A2C0.2020801@elischer.org> In-Reply-To: <20060816094944.GC820@turion.vk2pj.dyndns.org> References: <200608151627.37828.root@solink.ru> <20060815130002.M45647@fledge.watson.org> <200608160959.23100.root@solink.ru> <20060816094944.GC820@turion.vk2pj.dyndns.org>
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Peter Jeremy wrote: >On Wed, 2006-Aug-16 09:59:22 +0700, Bachilo Dmitry wrote: > > >>Oh, it's natd. Now I see, but I just don't get it. I know that natd is not >>efficient but, as I've said, at home I have 9 or almost 10 MB/sec through the >>natd, while at this particular server I see only 3,7 MB maximum. I've tried >>now to turn all the natting off and tried to download a file and got like 9 >>MB/sec, so it is natd who loads the system up. >> >> > >natd runs in userland so every packet has to be pushed out to userland, >processed and pushed back into the kernel. The vast majority of the >overhead is the userland/kernel transition so natd gives you a basically >fixed pps rate. Your throughput will vary depending on the packet size. > > in 6.1 there is an in kernel version of natd.. man ng_nat > > >>Someone advised me to use pf or ipnat, but I never did that before and heard >>that this nats have some limitations (like ipnat can't translate icmp packets >>or something). >> >> > >Some time ago, I switched from natd to ipnat at work because the >overhead was getting too much. (I've also switched hardware so I >can't give you direct performance comparisons). I have found some >problems with IPfilter in -stable when combining ipfilter/ipnat, >stateful filtering and conditional NATing (ie a packet to B gets NAT'd >to C only if it came from A). (The same combination works in IPfilter >3.x on Solaris.) Normal filtering and NATing works OK. > > >
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