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DHCPv6 vs. DHCPv4 Message Types Comparison

A comparative view of DHCPv6 and DHCPv4 message types is presented in the table below:

DHCPv6 Message TypeDHCPv4 Message Type

Solicit (1)


Advertise (2)


Request (3), Renew (5), Rebind (6)


Reply (7)


Release (8)


Information-Request (11)


Decline (9)


Confirm (4)


Reconfigure (10)


Relay-Forw (12), Relay-Reply (13)


Detailed Explanation of DHCPv6 Message Types:

  1. Solicit (1): Initiated by a DHCPv6 client to find available servers.

  2. Advertise (2): Sent by servers in response to a Solicit, indicating availability for DHCP service.

  3. Request (3): Clients use this to request IP addresses or prefixes from a specific server.

  4. Confirm (4): Used by a client to verify if the assigned addresses are still valid on the network, typically after a network change.

  5. Renew (5): Clients send this to the original server to extend address lifetimes or update configurations.

  6. Rebind (6): Sent to any server to extend address lifetimes or update configurations, especially when no response is received to a Renew.

  7. Reply (7): Servers use this to provide addresses, configuration parameters, or to acknowledge messages like Release or Decline.

  8. Release (8): Clients inform the server to stop using one or more assigned addresses.

  9. Decline (9): Sent by clients to report that assigned addresses are in conflict on the network.

  10. Reconfigure (10): Servers prompt clients to initiate transactions for new or updated configurations.

  11. Information-Request (11): Clients request configuration parameters without IP address assignment.

  12. Relay-Forw (12): Relay agents forward messages to servers.

  13. Relay-Repl (13): Servers reply to relay agents, who then deliver the message to the client.


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