106 IPv6ip ospf area 0.0.0.0exitinterface vlan 2routingipv6 enableipv6 address 2020:2::2/64ipv6 ospfipv6 ospf network point-to-pointexitinterface tunnel 0ipv6 address 2001::2/64tunnel mode ipv6iptunnel source 10.10.10.1tunnel destination 20.20.20.1ipv6 ospfipv6 ospf network point-to-pointexitinterface loopback 0ip address 2.2.2.2 255.255.255.0exitexitDHCPv6DHCP is generally used between clients (e.g., hosts) and servers (e.g., routers) for the purpose ofassigning IP addresses, gateways, and other networking definitions such as DNS, NTP, and/or SIPparameters. However, IPv6 natively provides for autoconfiguration of IP addresses through IPv6Neighbor Discovery Protocol (NDP) and through the use of Router Advertisement messages. Thus, therole of DHCPv6 within the network is different than that of DHCPv4 in that it is less relied upon for IPaddress assignment.DHCPv6 server and client interactions are described by RFC 3315 [6]. There are many similaritiesbetween DHCPv6 and DHCPv4 interactions and options, but the messages and option definitions aresufficiently different such that there is no DHCPv4 to DHCPv6 migration or interoperability.DHCPv6 incorporates the notion of the “stateless” server, where DHCPv6 is not used for IP addressassignment to a client; rather, it only provides other networking information such as DNS, NTP, and/orSIP information. The stateless server behavior is described by RFC 3736 [7], which simply containsdescriptions of the portions of RFC 3315 that are necessary for “stateless” server behavior. In order for arouter to drive a DHCPv6 client to utilize stateless DHCPv6, the “other stateful configuration” optionmust be configured for neighbor discovery on the corresponding IPv6 router interface. This, in turn,causes DHCPv6 clients to send the DHCPv6 “Information Request” message in response. A DHCPv6server then responds by providing only networking definitions such as DNS domain name and serverdefinitions, NTP server definitions, and/or SIP definitions.