From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Erik Ahlner" Subject: Should i be worried? Date: Tue, 28 Jan 2003 23:29:36 +0100 Sender: netfilter-admin@lists.netfilter.org Message-ID: <000c01c2c71c$bd541090$0200a8c0@whyzpc> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Errors-To: netfilter-admin@lists.netfilter.org List-Help: List-Post: List-Subscribe: , List-Id: List-Unsubscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii" To: netfilter@lists.netfilter.org Hello! I just happened to do a dmesg, and got this output: IN=eth0 OUT=eth0 SRC=192.168.0.186 DST=130.236.230.9 LEN=74 TOS=0x00 PREC=0x00 TTL=127 ID=14459 PROTO=UDP SPT=137 DPT=53 LEN=54 IN=eth0 OUT=eth0 SRC=192.168.0.186 DST=130.236.230.9 LEN=74 TOS=0x00 PREC=0x00 TTL=127 ID=14715 PROTO=UDP SPT=137 DPT=53 LEN=54 IN=eth0 OUT=eth0 SRC=192.168.0.88 DST=217.209.28.135 LEN=48 TOS=0x00 PREC=0x00 TTL=127 ID=37469 DF PROTO=TCP SPT=2418 DPT=80 WINDOW=16384 RES=0x00 SYN URGP=0 As you can see, i get some message about traffic from 192.168.0.186 and .88 .. these two computers are NOT in my home network, so i guess that someone has named his computers like that on the university network, even though the university network has 130.236.x.x. Is this a problem for me? And what does this output actually mean? Has someone used my computer as a router? If they have, how is that possible? This is what my iptable looks like: $IPTABLES -P INPUT ACCEPT $IPTABLES -F INPUT $IPTABLES -P OUTPUT ACCEPT $IPTABLES -F OUTPUT $IPTABLES -P FORWARD DROP $IPTABLES -F FORWARD $IPTABLES -t nat -F $IPTABLES -A FORWARD -i $EXTIF -o $INTIF -j ACCEPT $IPTABLES -A FORWARD -i $INTIF -o $EXTIF -j ACCEPT $IPTABLES -A FORWARD -j LOG $IPTABLES -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE $IPTABLES -A INPUT -s 192.168.0.0/24 -i eth0 -j DROP I thought that the last line was to stop this from happening.. Or am i just stupid? Did dmesg just show me that some packets have been dropped? Many thanks Erik Ahlner