Re: [PLUG] routing question....

["Eric Hidle" <junkmail@ie-ap.org>]

I know that the LARTC method will work with DCA.net DSL. DCA connections are
100% unfooled around with..

Thanks for the info about the rp_filter - I do remember having to disable
rp_filter for assymetric routing to work properly.

Doug, I can send you my setup script if you want it. You'd just have to
change the variables to suit your local setup...
E



----- Original Message ----- 
From: "Michael C. Toren" <mct@toren.net>
To: <plug@lists.phillylinux.org>
Sent: Monday, December 06, 2004 9:15 AM
Subject: Re: [PLUG] routing question....


> On Mon, Dec 06, 2004 at 01:24:10AM -0500, Doug Crompton wrote:
> > I am switching from PPP to Ethernet (DSL) and in the transition phase it
> > would be nice. It seems that different paths - EG. in on PPP out on DSL
> > or in on DSL out on PPP does not work. The data flows but the connection
> > never establishes.  Can't you have different RX/TX data paths?
>
> Asymmetric routing is indeed possible, however two items may be getting
> in your way.  The first is Linux's return-path verification, which as a
> security precaution attempts to permit only symmetric routing.  Debian
> enables rp_filter by default; I don't know what the default settings are
> for other distributions.  To disable it, simply execute the following:
>
> echo 0 > /proc/sys/net/ipv4/conf/eth0/rp_filter
> echo 0 > /proc/sys/net/ipv4/conf/ppp0/rp_filter
>
> The second item is that your upstream provider may also be implementing
> return-path verification to prevent their customers from spoofing packets.
> If you suspect this is the case, and if your dialup has a static IP, you
> may want to contact them and see if they would be willing to temporarily
> permit packets with a source address of your ppp0 through.
>
> > So instead of that, in a system with ppp0 and eth0 can you have the data
> > go out the same path in came in on with the same IP- in esscense two
route
> > defaults. All data that came in on ppp0 goes out on ppp0 and data in on
> > eth0 goes out on eth0.
>
> Yes, this is also possible.  One solution is to implement policy routing
> which will make routing decisions based on the source address rather than
> the destination address.  As Eric mentioned, the Linux Advanced Routing &
> Traffic Control (LARTC) HOWTO is an excellent resource for configurations
> such as this, and can be found at lartc.org.
>
> HTH,
> -mct
>
> -- 
> perl -e'$u="\4\5\6";sub H{8*($_[1]%79)+($_[0]%8)}sub G{vec$u,H(@_),1}sub
S{vec
> ($n,H(@_),1)=$_[2]}$_=q^{P`clear`;for$iX){PG($iY)?"O":"
"forX8);P"\n"}for$iX){
> forX8){$c=scalar
grep{G@$_}[$i-1Y-1Z-1YZ-1Y+1ZY-1ZY+1Z+1Y-1Z+1YZ+1Y+1];S$iY,G(
>
$iY)?$c=~/[23]/?1:0:$c==3?1:0}}$u=$n;select$M,$C,$T,.2;redo}^;s/Z/],[\$i/g;s
/Y
> /,\$_/xg;s/X/(0..7/g;s/P/print+/g;eval' #     Michael C. Toren
<mct@toren.net>
>
>
___________________________________________________________________________
> Philadelphia Linux Users Group         -- 
http://www.phillylinux.org
> Announcements -
http://lists.phillylinux.org/mailman/listinfo/plug-announce
> General Discussion  -- 
http://lists.phillylinux.org/mailman/listinfo/plug
>

___________________________________________________________________________
Philadelphia Linux Users Group         --        http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug