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swtbeer's avatar
swtbeer
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Mar 09, 2015

NAT (not SNAT) not preserving client source port

Hello ,   recently we've migrated our bigip-3600 to a new bigip400 platform. Everithing is working correctly except NATs.   Something has changed in the way ltm work with NATs.   With vers...
application delivery
LTM
management
swtbeer's avatar
swtbeer
Icon for Nimbostratus rankNimbostratus
Mar 10, 2015

Hi Stephan ,

 

the important point here isn't the client source port. What I need is that ltm keep the NAT connection working after 300 seconds timeout. It seems that in versión 9, NAT connections used "lost initiation" feature adding again the connection to the connection table without requiring a SYN packet. For this to work correctly is necessary that the client source port keeps unchanged.

 

In version 11 , ltm drops the connection without sending RST and it doesn't add it again when new trafic comes. I think is related to the client source port is changed.

 

I don't know if I'm explaining fine.

 

Regards