DHCPv6

Stateless DHCPv6 works in combination with StateLess Address AutoConfiguration (SLAAC), where an IPv6 host obtains its addressing information from information contained within route advertisements. However, the IPv6 host also queries a DHCPv6 server for additional information, such as DNS or NTP server addresses. The query for other configurations is triggered by the other-config-flag flag set in the route advertisements. The ipv6 nd other-config-flag command is used to configure IPv6 interface neighbor discovery to allow hosts to use a DHCPv6 server for additional information, such as DNS or NTP server addresses.
The managed-config-flag flag is set in route advertisements to tell IPv6 hosts to get their addressing and additional information only from the DHCPv6 server. This results in the client using the stateful DHCPv6 address assignment method, not the stateless DHCPv6 method. The ipv6 nd managed-config-flag command is used to set the managed-config-flag flag.
The ipv6 nd ns-interval command is used to configure the interval between IPv6 neighbor solicitation retransmissions on an interface. The ipv6 nd ns-interval command is not used to configure route advertisements to specify that the IPv6 DHCP client needs to use the stateless DHCPv6 address assignment method.
The ipv6 nd redirects command is used to configure neighbor redirect messages. Neighbor redirect messages are used to notify hosts of better first-hop nodes that are on the path to the destination. The ipv6 nd redirects command is not used to configure route advertisements to specify that the IPv6 DHCP client needs to use the stateless DHCPv6 address assignment method.

DHCPv6-PD is an extension to DHCPv6. Its task is to assign whole subnets from a DHCPv6 server to a DHCPv6 client. This means that, unlike classic DHCPv6 where a client receives a single address, the DHCPv6-PD client receives a set of subnets. The subnets can be segmented and dynamically applied to the client interfaces. A DHCPv6 client is usually a CPE device.
IPv6 StateLess Address AutoConfiguration (SLAAC) provides the ability to configure addressing information on host devices without any intervention from the network administrator. This configuration is achieved with the help of route advertisements that are sent by routers on the local link. Route advertisements contain one or more prefixes, prefix lifetime information, flag information, and default device information. IPv6 hosts listen for these route advertisements, takes the prefix advertised and generates the remaining 64 host bits. SLAAC does not provide the client with a set of subnets that can be segmented and dynamically applied to the client's interfaces.
When a stateful DHCPv6 server is implemented, the route advertisements need a way to tell IPv6 hosts to get their addressing and additional information only from the DHCPv6 server. This is achieved by setting the managed-config-flag flag in the route advertisements. This flag tells the hosts to disregard the prefixes in the route advertisements and query the DHCPv6 for addressing and other information. The server then allocates addresses to hosts and tracks the allocated addresses. Stateful DHCPv6 does not provide the client with a set of subnets that can be segmented and dynamically applied to the client's interfaces.
Stateless DHCPv6 works in combination with StateLess Address AutoConfiguration (SLAAC), where an IPv6 host obtains its addressing information from information contained within route advertisements. However, the IPv6 host also queries a DHCPv6 server for additional information, such as DNS or NTP server addresses. The query for other configurations is triggered by the other-config-flag flag set in the route advertisements. Because the DHCPv6 server never assigns any IPv6 addresses, it does not need to keep their state, which makes it stateless. Stateless DHCPv6 does not provide the client with a set of subnets that can be segmented and dynamically applied to the client's interfaces.