Hello Forum,
I have two networks and a OpenWRT router between them. The private network on the eth1 switch ports (192.168.0.1/24) and the public net on the wan port eth0 (192.168.1.1/24). I want to log udp packets coming from the public network, because there are some windows machines. They send udp broadcasts on port 137/138.
iptables -I INPUT -p udp -i eth0 -j LOG --log-level info --log-prefix "Windows UP "
What I dont understand is why this rule also logs my windows machines in the private net. For example this packet:
Windows UP IN=eth0 OUT= MAC=ff:ff:ff:ff:ff:ff:12:34:56:78:90:12:08:00 SRC=192.168.0.2 DST=192.168.0.255 LEN=78 TOS=0x00 PREC=0x00 TTL=128 ID=20514 PROTO=UDP SPT=137 DPT=137 LEN=58
On the eth0 interface is the 192.168.1.1/24 network and not the 0 net. Broadcasts like 192.168.0.255 should not be forwarded into the 192.168.1.0/24 net
root@LEDE:~# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.1.1 0.0.0.0 255.255.255.255 UH 0 0 0 eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
What could I reconfigured in the OpenWRT router?
Thanks a lot
Peter