From owner-FreeBSD-net-jp@jp.FreeBSD.org Fri Mar 15 09:32:59 2002
Received: (from daemon@localhost)
	by castle.jp.FreeBSD.org (8.11.6+3.4W/8.11.3) id g2F0WxG54606;
	Fri, 15 Mar 2002 09:32:59 +0900 (JST)
	(envelope-from owner-FreeBSD-net-jp@jp.FreeBSD.org)
Received: from shiva.tri.asanuma.co.jp (shiva.tri.asanuma.co.jp [210.160.188.2])
	by castle.jp.FreeBSD.org (8.11.6+3.4W/8.11.3) with ESMTP/inet id g2F0Wvc54436
	for <FreeBSD-net-jp@jp.freebsd.org>; Fri, 15 Mar 2002 09:32:57 +0900 (JST)
	(envelope-from mori@tri.asanuma.co.jp)
Received: from yashoda.tri.asanuma.co.jp (yashoda.tri.asanuma.co.jp [172.16.57.11])
	by shiva.tri.asanuma.co.jp (Postfix) with ESMTP id 705B95477
	for <FreeBSD-net-jp@jp.freebsd.org>; Fri, 15 Mar 2002 09:32:55 +0900 (JST)
Received: from kurishna.tri.asanuma.co.jp (kurishna.tri.asanuma.co.jp [172.16.57.2])
	by yashoda.tri.asanuma.co.jp (8.11.3nb1/8.11.3) with ESMTP id g2F0WsN20918
	for <FreeBSD-net-jp@jp.freebsd.org>; Fri, 15 Mar 2002 09:32:55 +0900 (JST)
To: FreeBSD-net-jp@jp.FreeBSD.org
References: <3C8EF21B.8080809@pop13.odn.ne.jp>
	<80pu28hnkr.fsf@kurishna.tri.asanuma.co.jp>
	<3C8F3B53.80901@pop13.odn.ne.jp>
	<80y9gwypdp.fsf@kurishna.tri.asanuma.co.jp>
	<3C906BBD.8060803@pop13.odn.ne.jp>
Siganture-File: ~/.signature
MIME-Version: 1.0 (generated by REMI 1.14.2 - =?ISO-2022-JP?B?IhskQiRbGyhC?=
 =?ISO-2022-JP?B?GyRCJC8kWyQvQmdFZxsoQiI=?=)
Content-Type: text/plain; charset=ISO-2022-JP
From: Mori Kouji <mori@tri.asanuma.co.jp>
Date: 15 Mar 2002 09:32:53 +0900
In-Reply-To: <3C906BBD.8060803@pop13.odn.ne.jp> (Isamu Kanakubo's message of "Thu, 14 Mar 2002 18:22:05 +0900")
Message-ID: <80bsdqoekq.fsf@kurishna.tri.asanuma.co.jp>
Lines: 53
User-Agent: Nana-gnus/7.1.0.23 REMI/1.14.2 (=?ISO-2022-JP?B?GyRCJFsbKEI=?=
 =?ISO-2022-JP?B?GyRCJC8kWyQvQmdFZxsoQg==?=) Chao/1.14.1
 (=?ISO-2022-JP?B?GyRCTztDT0IiGyhC?=) APEL/10.3 Emacs/21.1 (i386--freebsd)
 MULE/5.0 (=?ISO-2022-JP?B?GyRCOC1MWhsoQg==?=)
Reply-To: FreeBSD-net-jp@jp.FreeBSD.org
Precedence: list
X-Distribute: distribute version 2.1 (Alpha) patchlevel 24e+020312
X-Sequence: FreeBSD-net-jp 3596
Subject: [FreeBSD-net-jp 3596] Re: PPPoE =?ISO-2022-JP?B?GyRCJE4bKEI=?=
 ftp =?ISO-2022-JP?B?GyRCJE4/NiRrSXEkJBsoQg==?= 
Errors-To: owner-FreeBSD-net-jp@jp.FreeBSD.org
Sender: owner-FreeBSD-net-jp@jp.FreeBSD.org
X-Originator: mori@kurishna.tri.asanuma.co.jp

$B?9$G$9!#(B

Isamu Kanakubo <kanakubo@pop13.odn.ne.jp> writes:

> /usr/src/usr.sbin/ppp/tcpmss.c$B$r(BMAXMSS$B$C$F%^%/%m$rD>CM$G(B1000$B$H$+$K$7$F$_(B
> $B$?$N$G$9$,!"$=$l$G$b%@%a$G$7$?!#(B1000$B$^$G2<$2$l$P%V%i%C%/%[!<%k%k!<%?!<$b(B
> $BJ86g$r$$$o$J$$$H;W$&$N$G$9$,!"$I$&$G$7$g$&$+!)(B

$BKM$,CN$C$F$k(B PPPoE $B$,$i$_$NLdBj$O(B 3 $B$D$G$9!#(B

  1. PPP packet $B$N:GBg%5%$%:$r%+%W%;%k2=$9$k$H(B ether frame $B$N>e8B$J$I$r(B
     $B1[$($F$7$^$&!#$3$N>l9gAj<j$K$h$i$:DL?.>c32$,H/@8$9$k!#(B

  2. $B7PO)$N$&$A!"(BPPPoE $B$NItJ,$,B>$N$H$3$m$h$j(B MTU $B$,>.$5$$$?$a!"(B
     path MTU discovery $B$K>c32$,$"$k$H82:_2=$7$d$9$$!#(B
     $BFCDj$N7PO)$rDL2a$9$k>l9g(B($B$3$A$i$+$i$OFCDj$NAj<j$N$h$&$K8+$($k(B)$B$K(B
     $B$N$_>c32$,H/@8$9$k!#(B

  3. $B7PO)$N$&$A!"(BPPPoE $B$NItJ,$,B>$N$H$3$m$h$j(B MTU $B$,>.$5$$$?$a!"(B
     $B$=$NItJ,$G(B fragment $B2=$5$l$d$9$$!#FCDj$N(B OS (?) $B$N>l9g$K(B
     $B>c32$,H/@8$9$k!#(Bfragment $B2=$5$l$?%Q%1%C%H$OFO$/$N$G(B
     $B$3$A$i$,(B fragment $B2=$5$l$?%Q%1%C%H$r<N$F$J$1$l$PDL?.$O2DG=!#(B

$B$$$o$f$k%V%i%C%/%[!<%k%k!<%?LdBj$O(B 2 $B$KAjEv$7$^$9!#(B

# $B6b5WJ]$5$s$N$O>e$N(B 3 $B$D$N$I$l$H$b0[$J$k$h$&$K8+$($^$9!#(B

$B$=$l$>$l$NBP:v$O0J2<$N$h$&$K$J$j$^$9!#(B

  1. $B$"$i$+$8$a(B MTU $B$r>.$5$/$7$F$*$/!#(B(set max mtu $B$r@_Dj$9$k(B)

  2. MSS $B$rESCf$G=q$-49$($F!"(BPPPoE $B@\B3$rDL2a$G$-$k%5%$%:0J2<$N(B
     $B%5%$%:$N%Q%1%C%H$7$+Aw$i$J$$$h$&$K$9$k!#(B(4.4R $B0J9_$N(B ppp(8) $B$G$O(B
     $B%G%U%)%k%H$H$J$C$F$$$k(B)

  3. TCP $B$K%*%W%7%g%s%X%C%@$r4^$a$J$$$h$&$K$9$k$+(B MSS $B$r$b$C$H>.$5$/$9$k!#(B

3 $B$,5/$-$k>r7o$O$+$J$jFC<l$G!"(B

    i. $BAj<jB&$,(B path MTU discovery $B$r;H$C$F$*$i$:!"(B
   ii. $B$3$A$i$,DLCN$7$?(B MSS $B$N%5%$%:$$$C$Q$$$N%Q%1%C%H$r(B
  iii. fragment $B2=6X;_%U%i%0(B (DF) $B$r$D$1$J$$$GAw$C$F$/$k(B

$B$H$$$&>l9g$KH/@8$9$k$H9M$($i$l$^$9!#IaDL$O(B path MTU discovery $B$r(B
$B;H$C$F$J$1$l$P:G>.%5%$%:$N%Q%1%C%H$rAw$k$N$G>c32$O=P$^$;$s!#(B
(path MTU discovery $B$r;H$C$F$$$k$J$i(B DF $B$r$D$1$FAw$C$F$/$k$O$:$G$9(B)
$BAj<j$,(B DF $B$D$1$?%Q%1%C%H$rAw$C$F$/$k$N$G$"$l$P!"(BICMP $B%(%i!<$,JV$k$N$G(B
($BJV$i$J$$$N$,%V%i%C%/%[!<%k%k!<%?LdBj(B) $BAj<j$,$J$s$H$+$9$k$O$:!#(B

-- 
$B?9(B $B9@Fs(B	(MORI Kouji)
($B3t(B)$B^I>BAH(B $B5;=Q8&5f=j(B
E-mail: mori@tri.asanuma.co.jp
