iptables rule on INPUT between 2 ethernet cards on the same host
- by user1495181
I have 2 eth cards on the same host. Both connected directly with LAN cable.
I set eth0 with ip - 192.168.1.2
I set eth1 with ip - 192.168.1.1
I set this rule:
iptables -A INPUT -p tcp -j NFQUEUE --queue-num 0
There are no other rules. (I ran iptables -X,-F)
I send TCP syn packet ( with c++ program by using raw socket) from 192.168.1.2 to 192.168.1.1
In wireshark i see that the packet received on eth0, but the iptables rule (above) dosnt apply for this packet.
when i sent the packet to remote host and apply this rule on the remote host than it work correct.
So, i guess that this is due to the fact that both eth cards exists the same host.
.
I need to create iptables INPUT rule for local eth card (dest and src on the same machine ). I need it for simplify test.
Did i guess the problem correct? is there a way to bypass this?
Ps - connected them via switch didn't help. the rule wasn't applied.
Run on Ubuntu.
TCDUMP show the packet:
10:48:42.365002 IP 192.168.1.2.38550 > 192.168.1.1.34298: Flags [S], seq 0, win 5840, length 0
but logging of iptables like this, has nothing:
iptables -A INPUT -p tcp -j LOG --log-prefix '*****************'
iptables -A OUTPUT -p tcp -j LOG --log-prefix '#################'
