Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

JCK_171200's avatar
JCK_171200
Icon for Nimbostratus rankNimbostratus
Aug 24, 2017

SMTP VIP Configuration

I've created an application service for load balancing inbound SMTP mail. The firewall sends inbound SMTP mail to a VIP on the F5. The F5 sends the mail on to one of our two CAS servers and it gets...
application delivery
big-ip
irules
Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Aug 25, 2017

Hi JCK,

to overwrite the SNAT IP to the one used by your SMTP Virtual Server, you could simply attach the following iRule to your Virtual Server.

when CLIENT_ACCEPTED {
    snat [IP::local_addr]
}

... alternatively you could also create a SNAT pool containing the IP of your Virtual Server and then use 

snatpool "mypool"
instead of 
snat automap

Cheers, Kai