Is the IP protocol version 6 supported in Cisco Pix 515 UR ?If yes, is also IPv6 support in Cisco 515UR+FO4 ? (it it possible to make also IPv6 with the FO4 ethernet extension?)

Hello,I would like to buy 2 PIX 515 UR Firewalls and to link them with a serial cable.The two firewall's are connected on two different switches. If one switch fails I would like that the active Cisco pix firewall goes in standbye mode, and the secon...