User Manual UMN:CLI
V5808
361
DHCPv6 Address Assignment Mechanism
DHCP for IPv6 can provide stateful address configuration or stateless configuration
settings to IPv6 hosts. IPv6 hosts use several methods to configure addresses:
- Stateful Mechanism
It obtains interface address and configuration information from DHCP server. A site
requires tighter control over exact address assignment.
- Stateless Mechanism
It allows a host to generate its own address using a combination information
advertisement by routers. A site is not concerned with the exact address hosts use.
DHCPv6 Message Types
There are 13 DHCP message types. The following table summarizes the DHCP message
types.
Sent by clients to locate DHCPv6 servers.
Sent by server as a response to Solicit message received from a client to
indicate that it is available for DHCP service.
Sent by clients to request configuration parameters, including IP address
or delegated prefixes, from a specific server.
Sent by clients to verify that their address and configuration parameters
are still valid.
Sent by clients to renew their configuration parameters with their original
DHCP server when their lease is about to expire.
Sent by client to extend the lifetime of their address and renew their
configuration parameters with any DHCP server when their lease is
about to expire
Sent by DHCP servers responding to Request, Confirm, Renew, Rebind,
Release, and Decline messages.
Sent by clients to release their IP address
Sent by clients to indicate that one or more addresses assigned to them
are already in use on the link.
Sent by DHCP servers to inform clients that the server has new or
updated configuration information. The clients then must initiate a
request in order to obtain the updated information.
Sent by clients to request configuration parameters without the
assignment of any IP addresses to the client.
Sent by DHCP relays to forward client messages to servers. The relay
encapsulates the client message in an option in the relay-forward
message.
Sent by DHCP servers to send messages to clients through a relay. The
client message is encapsulated as an option in the relay-reply message.
The relay decapsulates the message and forwards it to the client.
Tab. 8.4 DHCPv6 Message Types