Yes, the first available interface will be mapped to eth0 of your BIG-IP VM and the next ones will show up in your VM as 1.1, 1.2 etc.
As all virtual interfaces are provided by the hypervisor you can access them from the hypervisor as well. I´m mapping the multiple VMs internally to the same virtual network interfaces. This allows traffic between your VMs. In addition I use a Debian VM to provide services as LDAP, RADIUS and others or to use it as a client (cURL, OpenSSL s_client, nc ...). Of course client applications as your different web browsers on desktop can be used this way as well to create requests to virtual servers.
In case I want to get access to one of the VMs from an external network I map the virtual network interface to a physical one by the hypervisor. If it´s just about outgoing requests i.e. for NTP sync the NAT mode of a virtual interface will be fine as well.
Actually I´m using this kind of environment since years. I´m using H/W appliances primarily to test specific HA scenarios, CMP related configs (now possible in VMs as well) and high-throughput scenarios. Everything else works pretty well for me in my BIG-IP VM lab editions.
Nimbostratus
