FTP Wrong Address from External IP

So here’s the thing, I have 2 virtualmin installations both running behind nat and both running on ubuntu server 12.04.

Virtualmin 1 is used for my website and Virtualmin 2 is used for my owncloud setup…

I have a local DNS server as well…

If i try to access the virtualmin 1 FTP from the local network i get a local adress for passive connection, if i access that same server from an external network it gives the client the external ip addess for the passive connection.

Working perfectly.

The second server however if i connect from an external network it gives the local ip adress for passive connection, i don’t use masquarading address in server 1 but somehow it knows when the connection is coming from an external network and when it’s coming from a local network and it gives the right adress the configuration is pretty much the same for both servers the only difference is that server 2 is using a different range of passive ports and server 1 is using port 21 while server 2 is using ‘2100’.

I can’t use masquarading address if i do i won’t be able to connect locally as it gives the external ip always, so what is wrong? what’s the difference between server 1 and 2?