[linux-users:102890] Re: $B%+!<%M(B$B%k%b!<%I(Bpppd$B$N(BMTU$B@_Dj$K(B$B$D$$$F(B

["hidetoshi(zefimia)" <zefimia@xxxxxxxxxxxxxxxxxx>]

$BJV?.$"$j$,$H$&$4$6$$$^$9!"Aa:d$G$9!#(B
(B
(B> iptables $B$N(B --clamp-mss-to-pmtu $B$O(B PMTU($Be!"(Bppp $B%$%s%?(B
(B> $B%U%'!<%9$N(B MTU?) $B$K9g$o$;$F(B forward $B$9$k%Q%1%C%H$NCf?H$r=q$-(B
(B> $B49$($k$b$N$G$9!#(B
(B> 
(B>   $B%k!<%?0J30$N%^%7%s(B($B%$%s%?!<%M%C%HB&(B/$B%$%s%H%i%M%C%HB&(B)$B$N(B MTU 
(B>   $B$,(B 1454 $B$G$J$$>l9g!"$=$l$i$,(B PMTU discovery $B$K<:GT$7$F$b!"(B
(B>   MSS $B$r=q$-49$($F$/$l$k$+$iBg>fIW(B
(B> 
(B> $B$H$$$&$N$,(B --clamp-mss-to-pmtu $B$G$O$J$$$G$7$g$&$+!#(B
(B
(BMSS$B$O(BMTU$B$+$i@_Dj$5$l$kCM!J$I$C$A$,@h$+$OD4$Y$F$^$;$s$,!&!&!&!K$G$O$J$$$s(B
$B$G$7$g$&$+!)(B
(Biptables(8)$B$r$_$k$H(B
(B
(B--clamp-mss-to-pmtu
(B              $B<+F0E*$K!"(BMSS $BCM$r(B (path_MTU - 40) $B$K6/@)$9$k!#(B
(B
$B$H=q$$$F$"$k$N$G!"(B--clamp-mss-to-pmtu$B$K@_Dj$9$k$H!"(BPathMTU$B$,<:GT$9$k4D6-$G$O(B
$B0UL#$,$J$$$H;W$C$F$$$^$7$?!#(BWeb$B%5%$%H$G8!:w$7$?:]$b!"(B
(B
(Bhttp://www.laser5.co.jp/update/embedded/lrouter/info/020705kernel.html
(B
$B$H!"(B--set-mss$B$r;H$C$F$$$?$N$G!"5?$$$J$/;H$C$F$$$^$7$?!#(B
(B
(B> > $B$?$@$7!"(Biptables$B$K$d$i$;$:$K!"(Bpppd$B$,D>@\$d$C$F$/$l$k$H(BCPU$BIi2YE*$K$OM%$7$$(B
(B> > $B5$$,$9$k$N$G!"(Bpppd$B$N(Bmtu$B$G@_Dj$G$-$k$N$,0lHV$G$9$M!#(B
(B> 
(B> pppd $B$O$"$/$^$G$b(B PPP $B$N%G!<%b%s$J$N$G!"(BPPP(PPPoE) $B$H$7$F$N(B 
(B> encode/decode $B$7$+$7$J$$$H;W$$$^$9!#(B
(B> 
(B> $B$J$N$G(B pppd $B$G$N(B mtu $B@_Dj$O!"$"$/$^$G$b(B ppp $B%$%s%?%U%'!<%9$N(B 
(B> MTU $B$r5,Dj$9$k$@$1$G!"$=$3$rDL$k%Q%1%C%H$NCf?H$r=q$-49$($k$o(B
(B> $B$1$G$O$J$$$G$7$g$&!#(B
(B
$B$J$k$[$I!#(B
(B
(B> $BCM$+$iA[A|$9$k$K!"$3$3$N(B mtu / mru $B$O(B PPP $B$N(B(!= PPPoE)$B$N(B
(B> MTU/MRU (PPP $B$N%Z%$%m!<%I$N%5%$%:(B) $B$G$O$J$$$G$7$g$&$+!#(B
(B> 
(B> # PPPoE $B$N>l9g$N(B MTU $B$,(B 1454 $B$J$N$G!"(B"oE"
(B> # (over ethernet)$BItJ,$,(B 38 byte? $BBg$-$$$G$9$M!D(B
(B>
(B> ps $B%3%^%s%I$N7k2L$H(B man $B%Z!<%8$rFI$a$P!"(BPPPoE $B$O(B
(B> plugin $B$H$7$F(B rp-pppoe.so $B$r8F$S=P$7$Fhttp://www.ietf.org/rfc/rfc2516.txt?number=2516
(B
$B$r8+$F$_$^$7$?!#(BPPPoE$BIt$O!"!"!"!"(B48Byte?
(BB$B%U%l%C%D$O;EMM$,0c$&$s$G$9$+$M!&!&!&!&$A$c$s$HM}2r$7$F$J$$$@$1(B
$B$@$H;W$&$N$G!"%M%C%H%o!<%/$NK\Gc$C$F$-$^$9!&!&!&!&(B
(B
(B> > P.S.
(B> > /sbin/adsl-connect$B$r(Bvi$B$G3+$-!"(Bmtu$B$r(B1454$B$K@_Dj$7$?$H$3$m!"B.EY$,Hs>o$KCY$/$J$j!"(B
(B> > $B2s@~$N@\B3$b@Z$l$k$h$&$K$J$C$F$7$^$$$^$7$?!#(Bpppd$B$N%3%^%s%I%i%$%s%*%W%7%g%s$O(B
(B> > $B8z2L$,L5$$$N$+$J$!!&!&!&!&!&(Bman$B$K$O@_Dj$G$-$k$H=q$$$F$"$C$?$N$G$9$,!#(B
(B> 
(B> $B$3$N;~!"(Bifocnfig ppp0 $B$H$+$7$F!"(Bppp $B%G%P%$%9$N(B MTU $B$r3N$+$a$^$7$?(B?
(B> $B$?$V$s(B MTU $B$,(B 1412 $B$H$+$K$J$C$F$?$N$G$O!D!#(B
(B
$B3N$+!&!&!&$J$s$G$9$,!"(Bifconfig$B$G$O(B1454$B$K$J$C$F$$$?$h$&$J!&!&!&!&(B
$B:#$O%5!<%P$K%"%/%;%9$,Mh$F$$$k>uBV$J$N$G!"2s@~$rMn$H$9$3$H$,$G$-$J$$$?$a!"(B
$B:FEY;n$;$J$$$N$G!"$A$g$C$HJ,$+$j$^$;$s!#:#EY;n83$G$-$k$H$-$K$d$C$F$_$^$9!#(B
(B
(BNTT$B$N7o$b$"$k$+$i!">iD99=@.$K$7$h$&$+$J!#(B
(B
$B$=$l$G$O!#(B