What address is DHCPv6 solicit messages sent?
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In this articleDHCP uses the following basic steps to automatically configure a network address and configuration information on a DHCP client. The application of DHCP discussed here is an illustrative example of an IPv4 network, where the DHCP client and the DHCP server are on the same subnet and the client machine has no prior IP address configured on the network interface. DHCP can also be used by a client to obtain configuration parameters (other than the IP address) from the DHCP server. For further details, see section 3.4 of [RFC2131].
The DHCPv4 client computer completes the TCP/IP initialization. It then repeats the preceding steps for other interfaces, if present, for which DHCP is enabled. (See the following figure.) After this is complete, the client can use all TCP/IP services and applications for normal network communications and connectivity to other IPv4 hosts. Figure 1: Basic DHCP process The DHCPv4 client can decline an offer from a DHCPv4 server if it determines that the IP address included in the DHCPOFFER message sent by the server is already in use on that network. If so, the DHCPv4 client sends a DHCPDECLINE message and restarts the configuration process by sending a DHCPDISCOVER message again. The DHCPv4 server can send a DHCPNAK message in response to the client's DHCPREQUEST message if one or more of the desired configuration options sent by the client in that message are unacceptable. In this case, the DHCPv4 client restarts the configuration process by sending a DHCPDISCOVER message again. The DHCPv4 client can relinquish its lease on the IP address by sending a DHCPRELEASE message to the server. In some cases, the DHCPv4 client can remember and want to reuse an IP address that was previously allocated by the DHCPv4 server to it. In this case, the client begins the initialization process by sending a DHCPREQUEST message to the server containing that network address as the "requested IP address". The DHCPv4 server sends a DHCPACK message to the client if it chooses to allow the client to continue to use that IP address. Otherwise, the DHCPv4 server sends a DHCPNAK message to the client. For further details on the DHCP protocol overview, refer to section 3 of [RFC2131]. DHCPv6 uses the following basic steps to automatically configure a network address on a DHCPv6 client. The application of DHCPv6 discussed here is an illustrative example of an IPv6 network. The DHCPv6 client and the DHCPv6 server are on the same subnet, and the client machine has no prior IPv6 address configured on the network interface. DHCPv6 can also be used by a client to obtain configuration parameters (other than the IP address) from the DHCPv6 server. Details are as specified in [RFC3315] sections 1, 18.1.5, and 18.2.5.
The presence of a Status Code option with any value other than Success in a DHCPv6 message from the server to the client is construed as a failure, and the DHCPv6 client then restarts the initialization process by sending the DHCPv6 Solicit message again. The DHCPv6 client computer completes the TCP/IP initialization as described in the preceding steps. It then repeats the preceding steps for other interfaces, if present, for which DHCPv6 is enabled. (See the following figure.) After this is complete, the client can use all TCP/IP services and applications for normal network communications and connectivity to other IPv6 hosts. Figure 2: Basic DHCPv6 process The DHCPv6 client can decline an offer from a DHCPv6 server if it finds that the IPv6 address included in the DHCPv6 Advertise message sent by the server is already in use on that network. If so, the DHCPv6 client sends a DHCPv6 Decline message and restarts the configuration process by sending a DHCPv6 Solicit message again. The DHCPv6 server can send a DHCPv6 Reply message with a Status Code option with a value other than Success in response to the client's DHCPv6 Request message if one or more of the desired configuration options sent by the client in that message are unacceptable. In this case, the DHCPv6 client restarts the configuration process by sending a DHCPv6 Solicit message again. The DHCPv6 client can relinquish its lease on the IP address by sending a DHCPv6 Release message to the server. In some cases, the DHCPv6 client can remember and want to reuse an IP address that was previously allocated by the DHCPv6 server to it. In this case, the client begins the initialization process by sending a DHCPv6 Renew or Rebind message to the server containing that network address as the "requested IP address". The DHCPv6 server sends a DHCPv6 Reply message with no Status Code option to the client if it chooses to allow the client to continue to use that IPv6 address. Otherwise, the DHCPv6 server sends a DHCP Reply message to the client with a value other than Success. For further details of the DHCPv6 protocol overview, see section 3 of [RFC3315]. Accidental configuration of multiple DHCP servers on a network might cause misconfiguration of DHCP clients. DHCP servers can implement Rogue Detection to prevent such accidental configurations. A Rogue Aware Server periodically checks whether it is authorized. Rogue Detection can be implemented using DHCPINFORM and/or DHCPv6 Information-request messages ([RFC3315] section 15.12). The following scenarios are valid for Rogue Detection: Authorization of a DHCPv4 server using DHCPINFORM.
Figure 3: DHCPv4 Server Authorization messages Authorization of a DHCP server using Information-request.
Figure 4: DHCPv6 Server Authorization messages What is DHCPv6 solicit message?The DHCP Solicit message is an IP multicast message sent by a client to one or more agents, or forwarded by a relay to one or more servers. The DHCP Advertise is an IP unicast message sent by a DHCP Agent in response to a client's DHCP Solicit message.
What is DHCPv6 address?DHCPv6 is a method to assign IPv6 addresses automatically to network clients. When you enable IPv6 for a trusted or optional interface, you can enable the DHCPv6 server on the interface, to assign IPv6 addresses to clients that connect. Before you can enable the DHCPv6 server, you must enable IPv6 for the interface.
What address is used to contact a DHCPv6 server?Which destination IP address is used when an IPv6 host sends a DHCPv6 SOLICIT message to locate a DHCPv6 server? DHCPv6 hosts will send a DHCP SOLICIT message to the all DHCP routers multicast address of FF02::1:2.
What are the normal DHCPv6 messages?A normal DHCPv6 message exchange involves the following messages: 1. Solicit - sent by a DHCPv6 Client to locate DHCPv6 Servers. 2. Advertise - sent by a DHCPv6 server to a DHCPv6 Client in answer to the solicit message as an affirmative message that DHCPv6 Server services are available to a DHCPv6 Client.
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