Below I have tried to copy the relevant things out of my filters. The rule should drop 
every thing except
packets to my internal network.

# Abbreviation for the iptables program:
I=/usr/local/sbin/iptables

ALLINTNETWORK="10.0.0.0"    # The 10.0.0.0/8 network
ALLINTNETMASK="255.0.0.0"
ALLINTNET="$ALLINTNETWORK/$ALLINTNETMASK"


INTIF="eth0"


$I -A if-LogDrop-int $LIMIT -j LOG --log-prefix "Bad input packet, internal: "
$I -A if-LogDrop-int -j DROP

$I -A if-LogDrop -i $INTIF -j if-LogDrop-int

$I -A i-int -s $ALLINTNET -j ACCEPT
$I -A i-int -j if-LogDrop

$I -A INPUT -i $INTIF -j i-int



Ramin Alidousti wrote:

> What/where is the rule which drops this packet? This is only the log...
>
> Ramin
>
> On Wed, Feb 27, 2002 at 09:47:53PM +0100, Torben Nielsen wrote:
>
> > It seems that the normal DHCP problem is to get it to work because the filters 
>drops the packets. My
> > problem to understand why DHCP work as my rules drops the DHCP broadcast request.
> >
> >
> > Feb 27 21:30:29 gandalf kernel: Bad input packet, internal: IN=eth0 OUT=
> > MAC=ff:ff:ff:ff:ff:ff:00:10:5a:b3:ba:a2:08:00 SRC=0.0.0.0 DST=255.255.255.255 
>LEN=328 TOS=0x00
> > PREC=0x00 TTL=128 ID=0 PROTO=UDP SPT=68 DPT=67 LEN=308
> > Feb 27 21:30:29 gandalf dhcpd: Dynamic and static leases present for 10.148.30.6.
> > Feb 27 21:30:29 gandalf dhcpd: Remove host declaration LD or remove 10.148.30.6
> > Feb 27 21:30:29 gandalf dhcpd: from the dynamic address pool for 10.148.30.0
> > Feb 27 21:30:29 gandalf dhcpd: DHCPREQUEST for 10.148.30.6 from 00:10:5a:b3:ba:a2 
>via eth0
> > Feb 27 21:30:29 gandalf dhcpd: DHCPACK on 10.148.30.6 to 00:10:5a:b3:ba:a2 via eth0
> >
> >
> > The first log is from my netfilter rule just before the packet (a DHCP broadcast) 
>is dropped. After
> > this the DHCP daemon starts to act on the packet as receiving the packet just 
>dropped. As far as I
> > can see by logging all packet there comes no new packets before the DHCP daemon 
>start to answer.
> >
> > Is there a simple explanation on this or do I have to try to reduce the complexity 
>of my filters so
> > they are understandelable without to much effort.
> >
> > Regards
> >
> > Torben
> >
> >


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