 address selection. Not only can the host itself have many addresses, but SO can the destination for which a new connection needs to be created. The host initiating connection can obtain a list of addresses for a destination, for example, via DNS. IETF has defined default source and destination address selection algorithms that hosts should follow when deciding which pairs of source and destination addresses to use and which order [92]. In practice, this prioritization is commonly done by the host's operating system at the time when an application requests DNS resolution or calls a connection creation method. The operating system either automatically creates a connection using, at first, addresses of the highest preference, or returns a list of destination addresses in priority order to the application calling the DNS resolution API function. Default Policy Table To help prioritizing IPv6 addresses - both source and destination - a default policy table has been defined in RFC 6724 [92] and illustrated in Table 3.3. The table lists the IPv6 prefix, a related precedence of that prefix over other prefixes (higher value means higher precedence), a label used to find pairs of source and destination addresses that have matching label, and a short description. The default policy table is, as the name states, a default. Hosts may override specific rules if they "know better", and it will also be possible to administratively alter the policy table on a host: the IETF is defining a new DHCPv6 option for provisioning hosts with site-specific address selection policies [89]. Source Address Selection The algorithm for source address selection works by taking a single destination IPv6 address at a time, and listing all source addresses that could be used to communicate with the destination address. The rules for selecting the preferred source address for the destination are briefly the following, in the priority order: 1. Prefer a source address that is the same as the destination address. In this case, communications are inte