I'm facing the problem, that my iptables rules aren't working anymore after I changed OS from Ubuntu 8.04 to Debian Squeeze.
I'm trying to do a Port Forwarding by
iptables -t nat -A PREROUTING -d $extip -i eth0 -p tcp -m tcp --dport 5777 -j DNAT --to-destination 192.168.10.169:5777 /proc/sys/net/ipv4/ip_forwarding is set All policies are set to ACCEPT 192.168.10.169 is in FORWARD chain
IP some_ip.33517 > ext_ip.5777: Flags [S], seq 3521672809, win 14600, options [mss 1450,sackOK,TS val 1691129923 ecr 0,nop,wscale 7], length 0 IP ext_ip.5777 > some_ip.33517: Flags [R.], seq 0, ack 3521672810, win 0, length 0
As you can see, there is a RST sent after SYN. I have no clue why this is happening.
I hope someone can help me. Thanks in advance.