Forum Discussion

Huwaihi_195804's avatar
Huwaihi_195804
Icon for Nimbostratus rankNimbostratus
Jul 28, 2015

SMTP inline load balancing with no SMTP greeting

We currently have two cisco IronPort Email Security Appliances that are load balances using the BIG IP. These appliances are placed behind the BIG IP (the BIG IP is their default gateway). When confi...
application delivery
deployment
design
devops
iRules
LTM
TMSH
Vernon_97235's avatar
Vernon_97235
Historic F5 Account
Jul 29, 2015

How do you have the Virtual Server configured? If it's a Standard TCP (with no higher layer profiles) or fastL4, then any response made by the server should be proxied through the BIG-IP. Have you had a chance to tcpdump to verify that the server is sending the greeting (I assume you mean the 220 initial message?) in both cases (i.e., with and without SNAT)?

 

  • Huwaihi_195804's avatar
    Huwaihi_195804
    Icon for Nimbostratus rankNimbostratus
    Jul 29, 2015
    The virtual server is configured with standard TCP. I do not understand the point regarding tcpdump (I know what tcpdump is, but I am not sure how to utilize it here). Yes, I am referring to the 220 initial message. This message is only appearing when snat is configured as automap.