... one more point. The 192.168.x.1 address is assigned to the host, so don't use it on a guest!
If you manually assign IP addresses to the guests, use 192.168.x.3 ... 192.168.x.127
192.168.x.1 is assigend to the host adapter
192.168.x.2 is used as the gateway in case of NAT
192.168.x.128... are used by the internal DHCP server
André