Starting with PIX software Version 5.1(2) the PIX 515-R allows owners to use a maximum of 3 interfaces. Customers are responsible for purchasing the 3rd interface. This is a free software upgrade for those customers with SMARTnet contracts and is available on CCO. Users who upgrade from an earlier version will need to obtain a new activation key from licensing@cisco.com. Customers who purchase a new 515-R with 5.1(2) preinstalled will not be affected. Software Version 5.2 or later does not require a new activation key for 3rd interface support.