Load balancing via a load balance such as an F5 will expose you to the issue of persistent connections generated from the upstream forwarder side. You will end up with most/all your connections going to a single intermediate regardless of the number that you have in your load balancing pool.
To counter this use multiple vip addresses and use atleast 2 destinations in each of the upstream F5 clients outputs.conf.
This way the data stream is broken and the load balancer will have a chance to redirect the traffic to another machine.
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