I wonder if anyone could help me out of this simple network problem. I have successfully setup a vnc for remote login to a host (VNC host) on my private network. Also, on the same host i have successfully setup a dynamic DNS called "csuk.dnsl.com". I know the VNC works because I tested it within the same subnet and it works. I have added port forwarding to my router and that works too.
I have 3 subnets One is the ADSL public address (SUBNET1) connect to my ISP and through this channel i get internet to my local network. The second subnet is the private network operated by my router which is 192.168.1.0 (SUBNET2) and my router IP is 192.168.254. The third subnet is a local network where all my PCs are connected to and the network address is 192.168.0.0 (SUBNET3).
In order to share my internet, my server has 2 NICs; NIC#1 has IP address 192.168.1.64 and NIC#2 has IP address 192.168.0.1. So NIC#1 is connected directly to the router while NIC#2 is connected to an internal hub.
The VNC host with the VNC server installed has NIC#3 with IP address 192.168.0.136.
Now, if i remote connected from any of host within subnet3 e.g. 192.168.0.73 and use NIC#3 IP address, no problem it connects and all is well.
However, if i use the dynamic DNS address which is csuk.dnsl.com, it fails to connect. The only way I could get my VNC host to receive external remote connections is if i move it from subnet#3 to subnet#2, that is, connect vnc host directly to the router and NIC#3 assumes an IP 192.168.1.68. Then no problem external remote connection to vnc is possible. Now, this is a pain, inconvenient and impractible since it only limits me to justs 3 VNC connections. And i know that most ISP public services buried in private subnets. So at this present time the vnc host is connected to subnet3 hence anyone who tries to connect will get a failed connection.
I hope someone can help me resolve this problem. What do i need to do.