Filtering traffic based on client ip address and URL

InquisitiveMai Is the port number in the clients request or on the server side.

*** DNS records ***
client1.example.com 300 IN A 1.1.1.1
client2.example.com 300 IN A 1.1.1.1

*** Clients side request example with port ***
https://client1.example.com:49152 -> F5 VS listening on 1.1.1.1:49152 -> pool members listening on <private_IP>:443
https://client2.example.com:49153 -> F5 VS listening on 1.1.1.1:49153 -> pool members listening on <private_IP>:443

*** Server side request example with port ***
https://client1.example.com -> F5 VS listening on 1.1.1.1:443 -> pool member listening on <private_IP>:49152
https://client2.example.com -> F5 VS listening on 1.1.1.1:443 -> pool member listening on <private_IP>:49153

In either of the client situation you can create an iRule that drops all hosts requests that are not for that specific client which will prevent from using the incorrect port for the associated client FQDN. In the second example if the client defined an alternate port the traffic would timeout because the F5 isn't listening on that port and it's the servers that are listening on the respective port behind the F5. You can create an iRule that says if host X comes in send them to pool X and if host Y comes in send them to pool Y. The irules would be the following, first the client and second the server.

# This is the iRule for client1.example.com Virtual Server
when CLIENT_ACCEPTED priority 500 {

    set DEFAULT_POOL [LB::server pool]

}

when HTTP_REQUEST priority 500 {

    set HOST [HTTP::uri]

    if { ${HOST} != "client1.example.com" } {
        drop
    }

}

# This is the iRule for client2.example.com Virtual Server
when CLIENT_ACCEPTED priority 500 {

    set DEFAULT_POOL [LB::server pool]

}

when HTTP_REQUEST priority 500 {

    set HOST [HTTP::uri]

    if { ${HOST} != "client2.example.com" } {
        drop
    }

}

# This is the iRule for combine Virtual Server listening on 443
when CLIENT_ACCEPTED priority 500 {

    set DEFAULT_POOL [LB::server pool]

}

when HTTP_REQUEST priority 500 {

    set HOST [HTTP::uri]

    switch --glob ${HOST} {
        "client1.example.com {
            pool POOL_client1_49152
        }
        "client2.example.com {
            pool POOL_client2_49153
        }
        default {
            # This is used if you have a generic website configured to direct clients to you for services
            pool ${DEFAULT_POOL}
        }
    }

}

If you can provide additional detail on the example communication flow we should be able to come up with a better iRule that will work for you. Please also keep in mind that when dealing with HTTPS communication this iRule would require that you are perform SSL termination on the F5.