Forum Discussion

Gabe's avatar
Gabe
Icon for Nimbostratus rankNimbostratus
Jan 29, 2018

In-Line SMTP with STARTTLS Offloading

We have a virtual server to load balance our SMTP/SMTPS traffic using SNAT Automap. It is currently performing TLS Offloading for STARTTLS but our SPAM Solution is not working properly since all the ...
application delivery
BIG-IP
security
Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Jan 29, 2018

Hi Gabriel,

 

Would TLS Offloading still work when we place the server in-line or does TLS offloading require SNAT Automap to be used ?

 

Yes it will work.

 

Beside of hiding the original source IP, the setting "snat none" or "snat auto" does not have an impact of the remaining TCP-Proxy/L7 functionality of LTM.

 

You can see it also like this "snat auto" is performing a SNAT to you floating IP and "snat none" is performing a SNAT to the same IP as before (aka. null-snat) for the server side TCP connection. And as long as your F5 is in the routing path for the responces of the server side connection, it makes no difference for the remaining functionality of your LTM...

 

Cheers, Kai