Forum Discussion

BaltoStar_12467's avatar
Dec 27, 2013

BIG-IP : how to determine Self-IP used by SNAT ?

BIG-IP 11.4.0 Build 2384.0 Final

 

On my Virtual Server , I have Source Address Translation = Auto-Map

 

( I believe this is the same as SNAT , correct ? )

 

How to determine the Self IP that BIG-IP will substitute-in as the origin IP when routing a request to a pool ?

 

  • Auto map is one form of SNAT. Secure (or source) network address translation is the method used to translate the client source address in a request to an address controlled by the proxy, usually for the purpose of controlling return routing. Auto map just uses the self-IP of the LTM as that source address, while a SNAT pool allows you to define specific non-self-IP addresses. Since a single IP address can only support about 64,000 simultaneous connections (based on available ports), a SNAT pool is often used when you might need more than that.

     

    If you have multiple self-IP addresses on the LTM, for different VLANs, the device will use the one that makes the most sense for routing.