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Date: Thu, 4 Jun 1998 12:17:09 +0900 (JST)
Message-Id: <199806040317.MAA10576@mail.hitachi-cable.co.jp>
From: Ito Kazumitsu <ito@htk.hitachi-cable.co.jp>
To: FreeBSD-users-jp@jp.freebsd.org
In-reply-to: <19980528120708H.nmiyo@hic.co.jp>
References: <199805271100.UAA21568@mail.hitachi-cable.co.jp> <19980528120708H.nmiyo@hic.co.jp>
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Subject: [FreeBSD-users-jp 29073] Re: Is IP_DF flag always set to 1?
Errors-To: owner-FreeBSD-users-jp@jp.freebsd.org
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$BF|N)EE@~$N0KF#$H?=$7$^$9!#(B

>   From: "MIYOKAWA, Nobuyoshi" <nmiyo@hic.co.jp>
>   Date: Thu, 28 May 1998 12:07:08 +0900

>   | $BF|N)EE@~$N0KF#$H?=$7$^$9!#(B
>   | 
>   | FreeBSD $B$N%^%7%s$+$iAw=P$5$l$k%Q%1%C%H$N(B IP $B%X%C%@$N(B IP_DF $B$,(B
>   | $B>o$K(B 1 $B$K$J$C$F$7$^$&$H$$$&8=>]$KG:$s$G$$$^$9!#(B
>   ...
>   | Ethernet $B$N(B MTU 1500 $B$.$j$.$j$N%Q%1%C%H$,!"1s3VCO$N(B
>   | $B%k!<%?$N(B MTU 1492 (IEEE 802.3) $B$N%$%s%?!<%U%'%$%9$K(B
>   | $B9T$/$H!"$=$3$G(B fragment $B$,$J$5$l$:$KGK4~$5$l$F$7$^$&!#(B

>     $B%=!<%9$rFI$`$N$,2<<j$J$N$G!"B?J,$K21B,$,:.$8$C$F$$$k$N$G$9(B
>   $B$,!"(B
>
>     1) MTU $BC5:w$r(B TCP $B$G$b$d$m$&!#(B
>     2) $B$=$l$K$O(B IP_DF $B$K(B 1 $B$rN)$F$J$/$A$c!#(B
>     3) $BAw?.$7$?%Q%1%C%H$,%U%i%0%a%s%HMW5a$G!"%(%i!<$K$J$C$?$h!#(B

$B$3$N%(%i!<$N8!CN$K$O!"$I$&$d$i!"(B `need fragmentation' ICMP $B$r(B
$B<u?.$9$k$3$H$,I,MW$H;W$o$l$^$9$,!"%(%i!<$NH/@885$,!"(BNAT $B5!G=IU(B
$B%k!<%?$d!"%Q%1%C%H%U%#%k%?%j%s%0$r$7$F$$$k%k!<%?$d!"(Bfirewall $B$r(B
$BB?CJ7PM3$7$?@h$K$"$j!"(B`need fragmentation' ICMP $B$r<u$1$k$3$H$O(B
$BE~Dl4|BT$G$-$^$;$s!#$H$$$&$o$1$G!"$=$b$=$b(B MTU discovery $B$H$$$&(B
$B$N$,5!G=$7$($J$$4D6-$G;H$C$F$$$?$h$&$G$9!#(B

>     $B$b$7;d$N21B,$,@5$7$1$l$P(B($B>/$J$/$H$b!"(B2.2.5R $B$N%=!<%9>e$G$O(B)$B!"(B
>
>   | $BBP>INEK!$H$7$F$O!"(BMTU $B$r@hJ}$K9g$o$;$F>.$5$/$9$k$H(B
>   | $B$$$&$3$H$G2?$H$+$J$j$=$&$G$9$,!"3d$j$-$l$J$$$b$N$r(B
>   | $B46$8$^$9!#(B
>
>   $B$9$k$7$+$J$5$=$&$J5$$,$7$^$9!#(B

$B$^$:$O!"$3$l$r$d$C$F$_$?$N$G$9$,!"2?8N$+$&$^$/$$$-$^$;$s$G$7$?!#(B
$B$7$+$b!"$=$l$^$G@5>o$KDL?.$G$-$F$$$?Aj<j08$N%Q%1%C%H$bGK4~$5$l(B
$B$k$h$&$K$J$C$F$7$^$$$^$7$?!#860x$O?<$/DI5Z$;$:!"$b$H$N@_Dj$K(B
$BLa$7$F!"(B


>   From: Ito Kazumitsu <ito@htk.hitachi-cable.co.jp>
>   Subject: [FreeBSD-users-jp 28786] Re: Is IP_DF flag always set to 1?
>   Date: Thu, 28 May 1998 10:47:17 +0900 (JST)
>   Message-ID: <199805280147.KAA27100@mail.hitachi-cable.co.jp>
>
>   | $B$H$"$j$^$9$,!"$3$N(B #if 1 ... #endif $B$N0U?^$O2?$J$N$G$7$g$&$+!#(B
>   | $B$3$l$r(B #if 0 $B$KJQ99$7$F%3%s%Q%$%k$7$F$bBg>fIW$G$7$g$&$+!#(B
>
>   $B$H=q$+$l$F$$$^$9$h$&$K!"(B#if 1 $B$r(B #if 0 $B$K$9$l$P(B TCP $B$N(B MTU
>   $BC5:w$O9T$o$l$J$$$h$&$J5$$,$7$^$9(B($B$,!"$3$l$ODj$+$G$O$"$j$^$;(B
>   $B$s(B)$B!#(B

$B$3$A$i$NBP:v$r;\$7$?$H$3$m!"(BFreeBSD $B$NF0:n$KLdBj$O8+$i$l$:!"(B
$B!V(BIP_DF $B$r%;%C%H$7$J$$$h$&$K$9$k!W$H$$$&L\E*$OC#@.$5$l$^$7$?!#(B

$B$7$+$7$J$,$i!"$=$l$G$b%Q%1%C%H$,GK4~$5$l$k$H$$$&8=>]$K2~A1$O(B
$B8+$i$l$^$;$s$G$7$?!#!VJ,3dIT2D$N%U%i%0$,N)$C$F$$$k$+$iJ,3d(B
$B$5$l$:$KGK4~$5$l$k!W$H$$$&$3$H$J$N$G6lO+$7$FBP:v$7$?$N$G$9$,!"(B
$B$I$&$b!"!VJ,3dIT2D$N%U%i%0$,N)$C$F$$$J$$$N$K!"J,3d$G$-$:$K(B
$BGK4~$7$F$7$^$&!W$H$$$&@hJ}$N%k!<%?$N%P%0$N2DG=@-$,G;8|$G$9!#(B

$B7k6I!"@hJ}$N%k!<%?$N@_Dj$rJQ99$7$F!"(BIEEE 802.3 $B$N;HMQ$r(B
$B$d$a$F$b$i$&$3$H$GLdBj$O2r7h$7$^$7$?(B ($B$O$8$a$+$i!"$=$l$G(B
$B2r7h$9$k$3$H$O8+$($F$$$?$N$G$9$,(B)$B!#(B

$B$H$$$&$o$1$G!"(BFreeBSD $B$K4X$7$F$O!"!V%=!<%9$r$$$8$k$N$G$O$J$/!"(B
$B9=@.Dj5A$N%*%W%7%g%s$G(B MTU discovery $B$r9T$J$o$J$$$h$&$K$G$-$?(B
$B$[$&$,$h$$$N$G$O$J$$$+!W$H0l;~E*$K$O;W$$$^$7$?$,!"!V(BMTU discovery $B$r(B
$B9T$J$&$h$&$K$J$C$F$$$F$b<B32$O$J$$!#LdBj$,@8$8$k$H$7$?$i!"(B
$B:,K\860x$O(B FreeBSD $B$N(B MTU discovery $B$H$OJL$N$H$3$m$K$"$k(B
$B2DG=@-$,9b$$!W$H$$$C$F$h$5$=$&$G$9!#(B

********************
Ito Kazumitsu <ito@htk.hitachi-cable.co.jp>

