Cirrus
MVPYou can configure and point users to an intermediary VS with an associated pool containing two members: your two mentioned VS. In these two VS, configure your connection limit or connection rate limit as per your requirement. If you want an active/backup scenario for your two VS you need to configure also priority group in the pool.
MVPteemo_13 definitely what Amine_Kadimi said. Another option is if you have a BIG-IP DNS license you can use health monitors on it to respond with specific destinations based on information it receives from that health monitor but it definitely wont be as responsive to connection limits as the virtual server option would be.
CirrusDoes this mean that I need to put another VS in front of my 2 existing VS? Another F5 device perhaps?
MVPYes, three VS all on the same device. The first is called the intermediary VS and it's the one facing your customers and which is load balancing to your two others called internal VS, those two can have any IP address even from a subnet not in your network, I usually use 203.0.113.0/24.
CirrusBased on this, we will be using iRule and not the normal VS as a Pool config?