Counting SMTP emails in Forwarding VS

Hi Guys When I throw myself in, I was expecting it to be an easy thing to do but I have kinda hit to the wall now. I am looking for ideas if we can achieve it indeed using IRule. We are using 6400 active/passive pair with 9.4.4 running on them.

 

 

REQUIREMENT

 

We have two Internet gateways facing gateways. We want to split the traffic between these gateways based on number of emails. For example, first 1,000 emails should use gateway_1 and rest should use gateway_2. It is a requirement that BIGIP should not proxy or relay the traffic, so we cannot have SMTP VS.

 

 

FORWARDING SOLUTION

 

What I have done so far is make a new Forwarding VIP (IP Forwarding) at the BIGIP and the IRule will be bound to this forwarding VS. We have a default gateway_2 defined as default gateway. IRule will count the emails and put an exception for gateway_1 for first 1,000 emails. Rest of all eamils will use default gateway of gateway_2 to reach the Internet mailing servers.

 

 

PROBLEM

 

The problem is, because Forwarding VS is a layer-3 VS, IRule function of TCP and SMTP are unable to work as we cannot bind TCP Profile to a Forwarding (IP) VSs. And to have TCP profile setup, we need STANDARD type of VS which will make the BIGIP proxy and break the requirement, so we cannot have STANDARD.

 

 

SUGGESTIONS REQUIRED My question is, can we somehow bind TCP Profile to a Forwarding (IP) VS? Or, can we look inside the IP PAYLOAD for SMTP commands or TCP session without having TCP Profile bound with VS? Which functions can I use in my IRule?

 

 

Any help will be greatly appreciated. Fire you questions to me if I did not explain well. Thanks.