The KS8999 contains eight 10/100 physical layer transceivers, nine MAC (Media Access Control) units with an integrated layer 2 switch. The device runs in two modes. The first mode is an eight port integrated switch and the second is as a nine port switch with the ninth port available through an MII (Media Independent Interface). Useful configurations include a stand alone eight port switch as well as a eight port switch with a routing element connected to the extra MII port. The additional port is also useful for a public network interfacing.The