NAT rule to change internal IP to another on same subnet?

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NAT rule to change internal IP to another on same subnet?

L4 Transporter

Hi folks,


I have created a internal zone IP address I want to use as generic for FTP communications

I want to NAT this IP to our current FTP server  This way when our FTP server changes we just change our NAT rule rather than the rest of our partner companies firewalls, routes, etc.


I've created a DNAT rule and able to ping and get a response from, but unable to connect via ftp.


I've done this before successfully between network zones (subnets) but not on the same zone (subnet) so far.


Any suggestions?


For it to work from outside you need:

From zone - Untrust

To zone - Untrust

Destination Address -

Service - create new tcp-21 with protocol tcp and port 21

Destination translation -


NB! Place this new wan rule above WebServer1 rule because otherwise WebServer1 will NAT all ports to

Enterprise Architect, Security @ Cloud Carib Ltd

Wow, thanks Raido!

I starting to get it.  I need to spend more time in wireshark to understand it better.


Thank you so much for your responses.  Creating this internal "VIP" will help in communicating a long term IP to our IPSec VPN connections that will allow us to change servers and IPs without the need to have our partners update their rules, etc.


Final NAT rules.




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