NAT Reflection, Which one to use?



  • Trying to get my internal devices working to hook into my exchange server. Using an iPad mail program to read my mails via exchange server. From what I have seen in videos I should be using Pure Nat but this is not working. If I use NAT and Proxy it works. Should I be using the NAT and Proxy or Pure NAT and if Pure NAT how do I get it to work?


  • LAYER 8 Global Moderator

    You should never use NAT reflection.. Unless you are forced too because some nonsense software hard coded an IP.. that is your public IP.. If your using dns - then you can just have your local dns resolve the fqdn to the actual local IP when your local.

    If you are using nat reflection then who ever wrote your software hard coding IP should be taken out back, not even given a cig or a blindfold and shot ;)



  • @johnpoz Don't be so harsh about nat reflection. It is nice sometimes.
    Eg mobile mail clients. When the laptop is away it reaches mail server as
    mymail.mycompany.com.
    If I don't have/use split dns then it won't work.
    And on top of that, what if someone has configured google dns, or even worse, has the mail ip on the configuration...
    Perhaps a gilotine must be installed at the backyard and all personell occurrences dealt with promptly.
    But I will need to convince the management first.



  • Using a mobile phone and iPad. The mobile phone works if I am outside my house away from my WiFi but once it hooks to my WiFi without NAT reflection on it wont connect. I have my phone set to use my dyndns FQDN and also my iPad. Outside of the internal works perfectly. Inside connected to the internal WiFi it doesn't. No hard coded IP's in the software. The Exchange server has a static IP and the incomming 443 connection to it is NAT Port forwarded to the IP of the exchange server.
    The port forwarding is why I assume it needs the NAT relection to work.



  • @veldthui Have you tried enabling options in system/advanced/ firewall and nat?


  • LAYER 8 Netgate

    NAT reflection is a hack. Split DNS is the way to do it.

    At the VERY LEAST, put the inside servers on a different subnet than the inside users so you are not trying to reflect people back into the same subnet they are connecting from.

    And after you do that, you can use simple port forwards on the user interface instead of a bunch of reflection.



  • Okay thanks for that. I think I have the split DNS working okay and will find out tomorrow when I turn the NAT reflection off.


Log in to reply