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AFAIK this should allow forwarding for the specified ports, and also forward all traffic on those ports to 192.168.0.5 (which is my client machine inside the LAN that runs the application).
So far, it's not working. What am I doing wrong?
To just clear my doubt, do you want to forward the SQL port from outside your network to the system inside your network? If that is so, can you just do a forwarding rule that will forward only the SQL port from outside to the system on specific SQL port? Check if this works.
1. App on Client PC (inside my LAN) sends a request on port 1433 to an SQL server on the Internet.
2. SQL Server on the internet acknowledges the transmission and wants to establish a link, sends reply on random port 1024 - 5000.
3. Traffic on ports 1024 - 5000 gets as far as my firewall, and then gets discarded.
I want to forward that traffic (3.) to my client computer inside my LAN (192.168.0.5)
I'm running with rule
$fw -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
If you can't stand up a VPN of some sorts (would be most elegant) the only
way I see is to forward all incoming traffic from the internet-based SQL
server to the client via firewall forwarding rules. Of course that won't
work if you have more than one client NATed (the VPN would still work).
Thanks for your replies so far. The posts you linked Lithos didn't help me too much.
Tinkster: I only have one client inside the LAN which uses the software that needs to communicate on those ports, but several other machines.
Is there really no way to make this work with port forwarding?