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Adel_Farhan_194's avatar
Adel_Farhan_194
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Aug 14, 2016

Source Address Persistence with Auto MAP configration

The our configuration of Source Address Translation as Auto MAP. So can we use Source Address Persistence? due to Auto MAP is using same source IP addresses  
application delivery
devops
LTM
janholtz's avatar
janholtz
Icon for Altostratus rankAltostratus
Aug 14, 2016

Sure. Understand that SNAT Automap changes the source of packets between F5 and ORIGIN servers. Source persistence creates a table of CLIENT IP / Pool member and uses the source IP of packets from the CLIENT system.

 

So CLIENT--->(F5 / persistence table) ----> Origin server.

 

If you were to cascade F5 devices (SNAT and THEN go to a vs with source persistence) THEN the persistence model would fail, since there would only ever be 1 entry in the persistence table.

 

So SNAT does not affect persistence tables on most deployments.

 

Personally, I prefer finding something else in the client request that is unique per session (cookies, usernames within the payload etc) and then doing a deterministic hash calc as to where to send the request. This way, no tables, and you can fail over between F5's with zero impact.. If you want (and to stop me rambling) I can submit a sample?

 

BR

 

Jan