We use F5 load balancer for delivering our apps across multiple data centres. There is an option to monitor load balancer in site24x7. However, its very limited. Only offers monitoring interfaces, bandwidth and standard performance counters such as CPU memory etc., but misses the key point why an organisation uses load balancer (is to deliver apps). You cannot treat load balalncers like a router.
The primary function of the load balancer is to publish web apps via LTM/GTM functionality and at a more granular level it does this using Wide IP, Virtual IP, Pool etc. Unfortunately I cannot monitor any of these key functions of a load balancer. I have attached two screenshots from my GTM and LTMS showing WIDE IPs, VIPs, Pools, nodes etc. This is only a partial list of apps we publish via load balancer.
It will be good to have site24x7 to monitor the status of a WIDE IP, Virtual IP, Pools and nodes in a load balancer. Without monitoring these key features, its useless to monitor a load balancer.