linuxbox (p.q.r.t) | | INTERNAL ------ ABCD ----- INTERNET (p.q.r.s) (m.n.o.k)
ABCD has 3 interfaces connected to linuxbox, INTERNAL N/W, INTERNET.
Linuxbox has a private address (p.q.r.t). At present I am snatting the packets from linuxbox to INTERNET at ABCD.
I have a small doubt regarding the FTP from linuxbox since I have to support ftp from linuxbox to both INTERNAL N/W as well as in INTERNET.
How can I right a rule in iptables present in ABCD where it can decide if the destination ip-address of ftp server is within INTERNAL N/W or in INTERNET and do natting accordingly.