I've got 2 servers, let's call them 'node1' and 'node2' installed at a data centre. They run our application software. They are interchangeable, and each have a full copy of all customers' databases. We want customers to be able to log into a single IP address, and have connections go to node1 if it's up, otherwise node2. (Automatic failover is more of a concern for us than load balancing, although in future we may configure load balancing too).
Our requirements are very simple: we can supply a URL to use as the health check, and if that's responding on 'node1' then all traffic should go there in preference to 'node2'.
The data-centre wants us to pay $3000 for a dedicated load balancer appliance. But they also say that their firewall has the ability to do this automatic failover _in_theory_, although they've never had a customer use that feature. I don't understand why such a simple task needs dedicated hardware or even a virtual server. Why wouldn't any small company prefer to do the load balancing in the firewall? It's less cost, less hops, less complexity...? What is it that I don't know about LTM (local traffic management)?