SMTP Load Balancing and Routing

Hi Don,

 

 

Here are some suggestions for your scenario:

 

 

I have two SMTP mail servers. I need to load balance them for an internal network, so that they may both send SMTP outbound. ... Mail coming from either of the mail servers would be NATted to an address on the external vlan.

 

 

 

For connections originating from the SMTP servers themselves, you could configure a 0.0.0.0:25 or :0 VIP enabled only on their VLAN with SNAT enabled. The SNAT could be a SNAT pool if you want to specify which IP(s) to use for the source address, or automap if you want to use the floating self IP(s) on the external VLAN. If you want to use the routing table for the outbound SMTP connections you could use a forwarding VIP. Else, if you have a pool of gateways you want to send the traffic to, you could add them to a pool and configure that pool as a gateway pool on the VIP.

 

 

I want to configure my F5 with two SMTP mail servers and a virtual server to be used for load-balancing from the internal network

 

 

 

You could configure a VIP enabled only on the internal VLAN pointing to a pool of the two SMTP servers.

 

 

From the external vlan (public internet) incoming SMTP connections would be sent to only one of the mail servers.

 

 

 

You could configure a second VIP enabled only on the external VLAN pointing to a pool of just one SMTP server.

 

 

Aaron