Is it possible to load balance w/out a load balancer?
Here is the scenario..
Our global email address is NAT'd internally...to two email servers..im wondering how it is possible to load balance between the two private IP addresses without a load balancer in the picture..would this be done at the firewall level, or is a router capable of doing this
I recommend you read the document I sent you because it has a lot of useful information regarding requirements and restrictions and design implementations.
The quick answer to your question is that you are correct on both counts.
1.) SLB will forward traffic sent to its virtual server farm address to each of the real server addresses and maintain a state table for all the connections. No NATing between the virtual server farm address and the real server addresses needs to be explicity configured.
However, (and this is why I suggested that you read the document), you can incorporate a reference to NAT in the configuration, which will allow you more flexibility by not having the requirement that the real servers be directly connected to the SLB switch. You won;t configure an actual NAT statement, however.
2.) You will configure a static NAT statement between the advertised global address for the email service and the virtual server farm address.
ip nat outside source static