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Forum Discussion

PKX9_161380's avatar
PKX9_161380
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Jun 19, 2014

How to configure f5 smtp vip to show client IP

I have a smtp vip configured with autosnat, but requests show the floatingIP as the clientIP. How do i get this to show the real client IP  
deployment
design
Cory_50405's avatar
Cory_50405
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Jun 19, 2014

You'd have to disable SNAT in order for the SMTP server on the backend to see the original client IP address. In order for this to happen, your SMTP server would need a route in place that forced return traffic to the client back through the LTM. For example, setting the default gateway on the SMTP server to the self IP address on the LTM. This may or may not be feasible depending on your environment.

 

  • PKX9_161380's avatar
    PKX9_161380
    Icon for Nimbostratus rankNimbostratus
    Jun 19, 2014
    And just to confirm, outbound smtp from the pool members will be seen as the smtp VIP or is it the floating IP of the loadbalancer?
  • Cory_50405's avatar
    Cory_50405
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    Jun 19, 2014
    For the SMTP flows initiated by your SMTP servers, you will likely need to setup a separate forwarding virtual server. You can enable SNAT on the forwarding virtual server to ensure it leaves the LTM on whatever VIP you like by specifying a SNAT pool.