Virtual services cannot been reached from the LAN side

Grace Chung 鍾素美 <gracec@xxxxxxxxxxxxxxx> · Fri, 11 Mar 2005 17:34:48 +0800

Hi everyone,

I have a FTP server on LAN side (192.168. 1.210), and a local host PC A(192.168.1.2).
My gateway has two interface,  eth0 (10.1.1.1) and eth1 (192.168.1.1).

I configure NAT as:
    iptables -t nat -A POSTROUTING -o  eth0 -j MASQUERADE
    iptables -t nat -A PREROUTING -p tcp -d 10.1.1.1 --dport 21 -j DNAT --to-destination 192.168.1.210
    iptabled -t nat -A POSTROUTING -p tcp --dport 21 -j SNAT --to_source 192.168.1.1

PC A try to connect to FTP server using : ftp 10.1.1.1
I monitor the traffic on the LAN 
    192.168.1.2     ->10.1.1.1             TCP SYN
    10.1.1.1            ->192.168.1.210     TCP SYN
    192.168.1.210    ->10.1.1.1         TCP SYN ACK
    192.168.1.1        ->192.168.1.2     TCP SYN ACK    <- should 10.1.1.1 ->192.168.1.2
    192.168.1.2        ->192.168.1.1    TCP RST

What rules do I apply it? Does anyone can help me? Thanks!

Grace