Cisco Systems Cisco Systems Cisco Systems This memo defines a Virtual Subnet Selection (VSS) option for each of DHCPv4 and DHCPv6, and a VSS sub-option carried in the DHCPv4 relay- agent-information option. These are intended for use by DHCP clients, relay agents, and proxy clients in situations where VSS information needs to be passed to the DHCP server for proper address or prefix allocation to take place. For the DHCPv4 option and relay-agent-information sub-option, this memo documents existing usage as per RFC 3942 [RFC3942]. This memo updates RFC 3046 [RFC3046] regarding details relating to copying of sub-options (see Section 8).