Date: Thu, 2 Apr 2015 19:46:32 +0100 (BST) From: Robert Watson <rwatson@FreeBSD.org> To: Hans Petter Selasky <hps@selasky.org> Cc: Mateusz Guzik <mjguzik@gmail.com>, Ian Lepore <ian@freebsd.org>, svn-src-all@freebsd.org, src-committers@freebsd.org, Gleb Smirnoff <glebius@FreeBSD.org>, svn-src-head@freebsd.org Subject: Re: svn commit: r280971 - in head: contrib/ipfilter/tools share/man/man4 sys/contrib/ipfilter/netinet sys/netinet sys/netipsec sys/netpfil/pf Message-ID: <alpine.BSF.2.11.1504021939390.64391@fledge.watson.org> In-Reply-To: <551D8C6C.9060504@selasky.org> References: <201504012226.t31MQedN044443@svn.freebsd.org> <1427929676.82583.103.camel@freebsd.org> <20150402123522.GC64665@FreeBSD.org> <20150402133751.GA549@dft-labs.eu> <20150402134217.GG64665@FreeBSD.org> <20150402135157.GB549@dft-labs.eu> <1427983109.82583.115.camel@freebsd.org> <20150402142318.GC549@dft-labs.eu> <20150402143420.GI64665@FreeBSD.org> <20150402153805.GD549@dft-labs.eu> <alpine.BSF.2.11.1504021657440.27263@fledge.watson.org> <551D8143.4060509@selasky.org> <551D8945.8050906@selasky.org> <8900318B-8155-4131-A0C3-3DE169782EFC@FreeBSD.org> <551D8C6C.9060504@selasky.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 2 Apr 2015, Hans Petter Selasky wrote: >>> Does somebody here know what happens in these two cases: >>> >>> If we are transmitting using TSO, will the network adapter increment the >>> IP ID field somehow? What happens if an outgoing IP packet resulting from >>> a TSO packet get fragmented by a router? >> >> Quite possibly -- this is presumably specified by the NIC vendor, but it >> would be good to do a bit of a survey and see what happens in practice. >> >>> In ip_fragment() when we create fragments we should increment the ip_id >>> value for each fragment? > > I'm asking because the code in FreeBSD, since the beginning probably, just > copies the IP header, and use the same IP ID for all the fragments ! This > just hit my mind after some recent work in this area. I honestly cannot believe you are proposing that. Please go read about how IP fragmentation works. Having an identical IP ID in ip_fragment() is the point of the function! Robert
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?alpine.BSF.2.11.1504021939390.64391>