[LARTC] IMQ and fwmark

[LARTC] IMQ and fwmark

[Daniel Brahneborg]

Hi all,

I want to divide the incoming traffic between what should go to
the firewall and what should be forwarded to the local network
behind it.  I started with the IMQ example config, but added an
extra htb class right below "10:1" to get the two sfq's to borrow
each other's bandwidth.

However, I can't figure out how to set the two marks.  According to
this picture, taken from http://lartc.org/lartc.html, I thought I could
set the marks in FORWARD and INPUT, but that didn't work at all.  The
traffic ends up in imq0 as it should, but only goes to the default
class.  Moving the '-j IMQ' to the INPUT and FORWARD tables didn't
work either.  What have I done wrong?

        +------------+                +---------+               +-------------+
Packet -| PREROUTING |--- routing-----| FORWARD |-------+-------| POSTROUTING |- Packets
input   +------------+    decision    +---------+       |       +-------------+    out
                             |                          |
                       +-------+                    +--------+   
                       | INPUT |---- Local process -| OUTPUT |
                       +-------+                    +--------+

iptables -t mangle -A INPUT   -i $EXTERNAL_INTERFACE -p tcp -j MARK --set-mark 0x1
iptables -t mangle -A FORWARD -i $EXTERNAL_INTERFACE -p tcp -j MARK --set-mark 0x2
iptables -t mangle -A PREROUTING -i $EXTERNAL_INTERFACE -j IMQ

/Basic

_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/

Re: [LARTC] IMQ and fwmark

[Andrew Hall]

Access to the IMQ interface sits between the mangle and DNAT tables in the
PREROUTING chain and after the connection tracking table in the POSTROUTING
chain. There isn't much point in setting marks for the IMQ from the INPUT
and FORWARD chains as these are traversed AFTER the IMQ interface
(PREROUTE). To correctly set the marks then you would need to set them in
the mangle table of the PREROUTE chain and do it based on address. Hope this
helps.

Andrew.
----- Original Message -----
From: "Daniel Brahneborg" <basic@chello.se>
To: "Linux Advanced Router & Traffic Control" <lartc@mailman.ds9a.nl>
Sent: Tuesday, July 29, 2003 6:55 PM
Subject: [LARTC] IMQ and fwmark


> Hi all,
>
> I want to divide the incoming traffic between what should go to
> the firewall and what should be forwarded to the local network
> behind it.  I started with the IMQ example config, but added an
> extra htb class right below "10:1" to get the two sfq's to borrow
> each other's bandwidth.
>
> However, I can't figure out how to set the two marks.  According to
> this picture, taken from http://lartc.org/lartc.html, I thought I could
> set the marks in FORWARD and INPUT, but that didn't work at all.  The
> traffic ends up in imq0 as it should, but only goes to the default
> class.  Moving the '-j IMQ' to the INPUT and FORWARD tables didn't
> work either.  What have I done wrong?
>
>         +------------+                +---------+
+-------------+
> Packet -| PREROUTING |--- routing-----| FORWARD |-------+-------|
POSTROUTING |- Packets
> input   +------------+    decision    +---------+       |
+-------------+    out
>                              |                          |
>                        +-------+                    +--------+
>                        | INPUT |---- Local process -| OUTPUT |
>                        +-------+                    +--------+
>
> iptables -t mangle -A INPUT   -i $EXTERNAL_INTERFACE -p tcp -j
MARK --set-mark 0x1
> iptables -t mangle -A FORWARD -i $EXTERNAL_INTERFACE -p tcp -j
MARK --set-mark 0x2
> iptables -t mangle -A PREROUTING -i $EXTERNAL_INTERFACE -j IMQ
>
> /Basic
>
> _______________________________________________
> LARTC mailing list / LARTC@mailman.ds9a.nl
> http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
>

_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/