BIG-IP BGP Routing Protocol Configuration And Use Cases

Now for a little bit on the difference between the network statement in BGP and the aggregate-address statement.

For the network statement to work by default back in the day, when dinosaurs configured routers with their little T-Rex hands there must be an exact match in the routing table. 

I say by default; because that was the default behavior and many of us packet heads after configuring our BGP statement, the next immediate command was 'no auto-summary'. Which now is the default and doesn't show up in the configuration anymore.

So now, let's look at your other suggestion of creating a /24 virtual server.

A lot of times, the /24 virtual server gets created as a "catch all" for the subnet. This can be a good thing in that I can log what hits IPs within the range that don't have a more specific virtual server attached to them. This is especially good if you're migrating things around. Like an application moves over to another network and you can see if for some reason that route isn't getting honored somewhere. There's lots of ways to have fun with it.

And yes, if it's tied to the failover traffic-group it will only be a kernel route on the active device. The problem will be that the route won't be withdrawn without some failure situation. In this case I would think about creating a pool and assign a monitor with an alias configuration that monitors something downstream.