Table Of Contents

Implementing DHCP for IPv6

Contents

Prerequisites for Implementing DHCP for IPv6

Restrictions for Implementing DHCP for IPv6

Information About Implementing DHCP for IPv6

DHCP for IPv6 Prefix Delegation

Configuring Nodes Without Prefix Delegation

Client and Server Identification

Rapid Commit

DHCP for IPv6 Client, Server, and Relay Functions

Client Function

Server Function

DHCP Relay Agent

How to Implement DHCP for IPv6

Configuring the DHCP for IPv6 Server Function

Configuring a Binding Database Agent for the Server Function

Configuring the DHCP for IPv6 Client Function

Configuring the DHCP for IPv6 Relay Agent

Configuring the Stateless DHCP for IPv6 Function

Configuring the DHCP for IPv6 Server Options

Defining a General Prefix with the DHCP for IPv6 Prefix Delegation Client Function

Restarting the DHCP for IPv6 Client on an Interface

Deleting Automatic Client Bindings from the DHCP for IPv6 Binding Table

Troubleshooting DHCP for IPv6

Verifying DHCP for IPv6 Configuration and Operation

Examples

Configuration Examples for Implementing DHCP for IPv6

Configuring the DHCP for IPv6 Server Function: Example

Configuring the DHCP for IPv6 Client Function: Example

Configuring a Database Agent for the Server Function: Example

Configuring the Stateless DHCP for IPv6 Function: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Feature Information for Implementing DHCP for IPv6

Implementing DHCP for IPv6

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First Published: June 26, 2006

Last Updated: July 19, 2007

The "Implementing DHCP for IPv6" module describes how to configure Dynamic Host Configuration Protocol (DHCP) for IPv6 prefix delegation on your networking devices. General prefixes can be defined in several ways: manually, based on a 6to4 interface, and dynamically, from a prefix received by a DHCP for IPv6 prefix delegation client.

Finding Feature Information in This Module

Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for Implementing DHCP for IPv6" section or the "Start Here: Cisco IOS Software Release Specifics for IPv6 Features" document.

Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

•Prerequisites for Implementing DHCP for IPv6

•Restrictions for Implementing DHCP for IPv6

•Information About Implementing DHCP for IPv6

•How to Implement DHCP for IPv6

•Configuration Examples for Implementing DHCP for IPv6

•Additional References

•Feature Information for Implementing DHCP for IPv6

Prerequisites for Implementing DHCP for IPv6

This document assumes that you are familiar with IPv4. See the publications referenced in the "Additional References" section for IPv4 configuration and command reference information.

Restrictions for Implementing DHCP for IPv6

Cisco IOS Release 12.0S provides IPv6 support on Cisco 12000 series Internet routers and Cisco 10720 Internet routers only.

Information About Implementing DHCP for IPv6

To configure DHCP for IPv6 for Cisco IOS software, you must understand the following concept:

•DHCP for IPv6 Prefix Delegation

DHCP for IPv6 Prefix Delegation

The DHCP for IPv6 prefix delegation feature can be used to manage link, subnet, and site addressing changes. DHCP for IPv6 can be used in environments to deliver stateful and stateless information:

•Stateful—Address assignment is centrally managed and clients must obtain configuration information not available through protocols such as address autoconfiguration and neighbor discovery.

•Stateless—Stateless configuration parameters do not require a server to maintain any dynamic state for individual clients, such as Domain Name System (DNS) server addresses and domain search list options.

The DHCP for IPv6 implementation in Cisco IOS Release 12.3(4)T and Cisco IOS Release 12.0(32)S support only stateless address assignment.

Extensions to DHCP for IPv6 also enable prefix delegation, through which an Internet service provider (ISP) can automate the process of assigning prefixes to a customer for use within the customer's network. Prefix delegation occurs between a provider edge (PE) device and customer premises equipment (CPE), using the DHCP for IPv6 prefix delegation option. Once the ISP has delegated prefixes to a customer, the customer may further subnet and assign prefixes to the links in the customer's network.

Configuring Nodes Without Prefix Delegation

Stateless DHCP for IPv6 allows DHCP for IPv6 to be used for configuring a node with parameters that do not require a server to maintain any dynamic state for the node. The use of stateless DHCP is controlled by router advertisement (RA) messages multicated by routers. The Cisco IOS DHCP for IPv6 client will invoke stateless DHCP for IPv6 when it receives an appropriate RA. The Cisco IOS DHCP for IPv6 server will respond to a stateless DHCP for IPv6 request with the appropriate configuration parameters, such as the DNS servers and domain search list options.

Client and Server Identification

Each DHCP for IPv6 client and server is identified by a DHCP unique identifier (DUID). The DUID is carried in the client identifier and server identifier options. The DUID is unique across all DHCP clients and servers, and it is stable for any specific client or server. DHCP for IPv6 uses DUIDs based on link-layer addresses for both the client and server identifier. The device uses the MAC address from the lowest-numbered interface to form the DUID. The network interface is assumed to be permanently attached to the device.

Rapid Commit

The DHCP for IPv6 client can obtain configuration parameters from a server either through a rapid two-message exchange (solicit, reply) or through a normal four-message exchange (solicit, advertise, request, reply). By default, the four-message exchange is used. When the rapid-commit option is enabled by both client and server, the two-message exchange is used.

DHCP for IPv6 Client, Server, and Relay Functions

The DHCP for IPv6 client, server, and relay functions are mutually exclusive on an interface. When one of these functions is already enabled and a user tries to configure a different function on the same interface, one of the following messages is displayed: "Interface is in DHCP client mode," "Interface is in DHCP server mode," or "Interface is in DHCP relay mode."

The following sections describe these functions:

•Client Function

•Server Function

•DHCP Relay Agent

Client Function

The DHCP for IPv6 client function can be enabled on individual IPv6-enabled interfaces.

The DHCP for IPv6 client can request and accept those configuration parameters that do not require a server to maintain any dynamic state for individual clients, such as DNS server addresses and domain search list options. The DHCP for IPv6 client will configure the local Cisco IOS stack with the received information.

The DHCP for IPv6 client can also request the delegation of prefixes. The prefixes acquired from a delegating router will be stored in a local IPv6 general prefix pool. The prefixes in the general prefix pool can then be referred to from other applications; for example, the general prefix pools can be used to number router downstream interfaces.

Server Selection

A DHCP for IPv6 client builds a list of potential servers by sending a solicit message and collecting advertise message replies from servers. These messages are ranked based on preference value, and servers may add a preference option to their advertise messages explicitly stating their preference value. If the client needs to acquire prefixes from servers, only servers that have advertised prefixes are considered.

IAPD and IAID

An Identity Association for Prefix Delegation (IAPD) is a collection of prefixes assigned to a requesting router. A requesting router may have more than one IAPD; for example, one for each of its interfaces.

Each IAPD is identified by an identity association identification (IAID). The IAID is chosen by the requesting router and is unique among the IAPD IAIDs on the requesting router. IAIDs are made consistent across reboots by using information from the associated network interface, which is assumed to be permanently attached to the device.

Server Function

The DHCP for IPv6 server function can be enabled on individual IPv6-enabled interfaces.

The DHCP for IPv6 server can provide those configuration parameters that do not require the server to maintain any dynamic state for individual clients, such as DNS server addresses and domain search list options. The DHCP for IPv6 server may be configured to perform prefix delegation.

All the configuration parameters for clients are independently configured into DHCP for IPv6 configuration pools, which are stored in NVRAM. A configuration pool can be associated with a particular DHCP for IPv6 server on an interface when it is started. Prefixes to be delegated to clients may be specified either as a list of preassigned prefixes for a particular client or as IPv6 local prefix pools that are also stored in NVRAM. The list of manually configured prefixes or IPv6 local prefix pools can be referenced and used by DHCP for IPv6 configuration pools.

The DHCP for IPv6 server maintains an automatic binding table in memory to track the assignment of some configuration parameters, such as prefixes between the server and its clients. The automatic bindings can be stored permanently in the database agent, which can be, for example, a remote TFTP server or local NVRAM file system.

Configuration Information Pool

A DHCP for IPv6 configuration information pool is a named entity that includes information about available configuration parameters and policies that control assignment of the parameters to clients from the pool. A pool is configured independently of the DHCP for IPv6 service and is associated with the DHCP for IPv6 service through the command-line interface (CLI).

Each configuration pool can contain the following configuration parameters and operational information:

•Prefix delegation information, which could include:

–A prefix pool name and associated preferred and valid lifetimes

–A list of available prefixes for a particular client and associated preferred and valid lifetimes

•A list of IPv6 addresses of DNS servers

•A domain search list, which is a string containing domain names for DNS resolution

Prefix Assignment

A prefix-delegating router (DHCP for IPv6 server) selects prefixes to be assigned to a requesting router (DHCP for IPv6 client) upon receiving a request from the client. The server can select prefixes for a requesting client using static assignment and dynamic assignment mechanisms. Administrators can manually configure a list of prefixes and associated preferred and valid lifetimes for an IAPD of a specific client that is identified by its DUID.

When the delegating router receives a request from a client, it checks if there is a static binding configured for the IAPD in the client's message. If a static binding is present, the prefixes in the binding are returned to the client. If no such a binding is found, the server attempts to assign prefixes for the client from other sources.

The Cisco IOS DHCP for IPv6 server can assign prefixes dynamically from an IPv6 local prefix pool. When the server receives a prefix request from a client, it attempts to obtain unassigned prefixes from the pool. After the client releases the previously assigned prefixes, the server returns them to the pool for reassignment.

An IPv6 prefix delegating router can also select prefixes for a requesting router based on an external authority such as a RADIUS server using the Framed-IPv6-Prefix attribute. For more information on this feature, see the Implementing ADSL and Deploying Dial Access for IPv6 module.

Automatic Binding

Each DHCP for IPv6 configuration pool has an associated binding table. The binding table contains the records about all the prefixes in the configuration pool that have been explicitly delegated to clients. Each entry in the binding table contains the following information:

•Client DUID

•Client IPv6 address

•A list of IAPDs associated with the client

•A list of prefixes delegated to each IAPD

•Preferred and valid lifetimes for each prefix

•The configuration pool to which this binding table belongs

•The network interface on which the server that is using the pool is running

A binding table entry is automatically created whenever a prefix is delegated to a client from the configuration pool, and it is updated when the client renews, rebinds, or confirms the prefix delegation. A binding table entry is deleted when the client releases all the prefixes in the binding voluntarily, all prefixes' valid lifetimes have expired, or administrators run the clear ipv6 dhcp binding command.

Binding Database

The automatic bindings are maintained in RAM and can be saved to some permanent storage so that the information about configuration such as prefixes assigned to clients is not lost after a system reload or power down. The bindings are stored as text records for easy maintenance. Each record contains the following information:

•DHCP for IPv6 pool name from which the configuration was assigned to the client

•Interface identifier from which the client requests were received

•The client IPv6 address

•The client DUID

•IAID of the IAPD

•Prefix delegated to the client

•The prefix length

•The prefix preferred lifetime in seconds

•The prefix valid lifetime in seconds

•The prefix expiration time stamp

•Optional local prefix pool name from which the prefix was assigned

At the beginning of the file, before the text records, a time stamp records the time when the database is written and a version number, which helps differentiate between newer and older databases. At the end of the file, after the text records, the text string "*end*" is stored to detect file truncation.

The permanent storage to which the binding database is saved is called the database agent. Database agents include FTP and TFTP servers, RCP, flash file system, and NVRAM.

DHCP for IPv6 Server Stateless Autoconfiguration

Hierarchical DHCP for IPv6 for stateless configuration parameters allows a stateless or stateful DHCP for IPv6 client to export configuration parameters (DHCP for IPv6 options) to a local DHCP for IPv6 server pool. The local DHCP for IPv6 server can then provide the imported configuration parameters to other DHCP for IPv6 clients.

Figure 1 shows a typical broadband deployment.

Figure 1 Broadband Topology

The CPE interface toward the PE can be a stateless or stateful DHCP for IPv6 client. In either case, the ISP-side DHCP for IPv6 server may provide configuration parameters such as DNS server addresses, domain names, and Simple Network Time Protocol (SNTP) servers to the DHCP client on the CPE. These information can be specific to an ISP and may change.

In addition to being a DHCP for IPv6 client (for example, toward the ISP), the CPE may act as a DHCP for IPv6 server to the home network. For example, Neighbor Discovery followed by stateless or stateful DHCP for IPv6 can occur on the link between CPE and the home devices (for example, the home router or PC). In some cases, the information to be provided to the home network is the same information obtained from the ISP-side DHCP for IPv6 server. Because this information can be dynamically changed, it cannot be hard-configured in the CPE's configuration. Therefore, the DHCP for IPv6 component on the CPE allows automatic importing of configuration parameters from the DHCP for IPv6 client to the DHCP for IPv6 server pool.

DHCP for IPv6 provides support of the options for IPv6 on the server described in the following sections:

•Information Refresh Server Option

•NIS- and NIS+-Related Server Options

•SIP Server Options

•SNTP Server Option

Information Refresh Server Option

The DHCP for IPv6 information refresh option can specify an upper boundary for the length of time a client should wait before refreshing information retrieved from DHCP for IPv6. This option is used with stateless DHCP for IPv6, because there are no addresses or other entities with lifetimes that can tell the client when to contact the DHCP for IPv6 server to refresh its configuration.

NIS- and NIS+-Related Server Options

Users can configure the network information service (NIS) or NIS plus (NIS+) address or domain name of a DHCP for IPv6 server using NIS- and NIS+-related options, and then import that information to the DHCP for IPv6 client.

SIP Server Options

Session initiation protocol (SIP) server options contain either a list of domain names or IPv6 addresses that can be mapped to one or more SIP outbound proxy servers. One option carries a list of domain names, and the other option carries a list of 128-bit IPv6 addresses.

SIP is an application-layer control protocol that can establish, modify and terminate multimedia sessions or calls. A SIP system has several logical components: user agents, proxy servers, redirect servers, and registrars. User agents may contain SIP clients; proxy servers always contain SIP clients.

SNTP Server Option

The SNTP server option provides a list of one or more IPv6 addresses of SNTP servers available to the client for synchronization. The clients use these SNTP servers to synchronize their system time to that of the standard time servers. The server may list the SNTP servers in decreasing order of preference, but clients must treat the list of SNTP servers as an ordered list.

DHCP Relay Agent

A DHCP relay agent, which may reside on the client's link, is used to relay messages between the client and server. DHCP relay agent operation is transparent to the client. A client locates a DHCP server using a reserved, link-scoped multicast address. Therefore, it is a requirement for direct communication between the client and the server that the client and the server be attached to the same link. However, in some situations in which ease of management, economy, or scalability is a concern, it is desirable to allow a DHCP client to send a message to a DHCP server that is not connected to the same link.

How to Implement DHCP for IPv6

The tasks in the following sections explain how to implement DHCP for IPv6:

•Configuring the DHCP for IPv6 Server Function

•Configuring the DHCP for IPv6 Client Function

•Configuring the DHCP for IPv6 Relay Agent

•Configuring the Stateless DHCP for IPv6 Function

•Configuring the DHCP for IPv6 Server Options

•Defining a General Prefix with the DHCP for IPv6 Prefix Delegation Client Function

•Restarting the DHCP for IPv6 Client on an Interface

•Deleting Automatic Client Bindings from the DHCP for IPv6 Binding Table

•Troubleshooting DHCP for IPv6

Configuring the DHCP for IPv6 Server Function

This task explains how to create and configure the DHCP for IPv6 configuration pool and associate the pool with a server on an interface.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp pool poolname

4. domain-name domain

5. dns-server ipv6-address

6. prefix-delegation ipv6-prefix/prefix-length client-DUID [iaid iaid] [lifetime]

7. prefix-delegation pool poolname [lifetime {valid-lifetime | preferred-lifetime}]

8. exit

9. interface type number

10. ipv6 dhcp server poolname [rapid-commit] [preference value] [allow-hint]

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp pool poolname Example: Router(config)# ipv6 dhcp pool pool1	Configures a DHCP for IPv6 configuration information pool and enters DHCP for IPv6 pool configuration mode.
Step 4	domain-name domain Example: Router(config-dhcp)# domain-name example.com	Configures a domain name for a DHCP for IPv6 client.
Step 5	dns-server ipv6-address Example: Router(config-dhcp)# dns-server 2001:0DB8:3000:3000::42	Specifies the DNS IPv6 servers available to a DHCP for IPv6 client.
Step 6	prefix-delegation ipv6-prefix/prefix-length client-DUID [iaid iaid] [lifetime] Example: Router(config-dhcp)# prefix-delegation 2001:0DB8:1263::/48 0005000400F1A4D070D03	Specifies a manually configured numeric prefix to be delegated to a specified client's IAPD.
Step 7	prefix-delegation pool poolname [lifetime {valid-lifetime | preferred-lifetime}] Example: Router(config-dhcp)# prefix-delegation pool prefix-pool 1800 60	Specifies a named IPv6 local prefix pool from which prefixes are delegated to DHCP for IPv6 clients.
Step 8	exit Example: Router(config-dhcp)# exit	Exits DHCP for IPv6 pool configuration mode configuration mode, and returns the router to global configuration mode.
Step 9	interface type number Example: Router(config)# interface serial 3	Specifies an interface type and number, and places the router in interface configuration mode.
Step 10	ipv6 dhcp server poolname [rapid-commit] [preference value] [allow-hint] Example: Router(config-if)# ipv6 dhcp server dhcp-pool	Enables DHCP for IPv6 on an interface.

Configuring a Binding Database Agent for the Server Function

This task shows how to configure a DHCP for IPv6 binding database agent for the server function.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp database agent-URL [write-delay seconds] [timeout seconds]

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp database agent-URL [write-delay seconds] [timeout seconds] Example: Router(config)# ipv6 dhcp database tftp://10.0.0.1/dhcp-binding	Specifies DHCP for IPv6 binding database agent parameters.

Configuring the DHCP for IPv6 Client Function

General prefixes can be defined dynamically from a prefix received by a DHCP for IPv6 prefix delegation client. This task shows how to configure the DHCP for IPv6 client function on an interface and enable prefix delegation on an interface. The delegated prefix is stored in a general prefix.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 dhcp client pd {prefix-name | hint ipv6-prefix} [rapid-commit]

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	interface type number Example: Router(config)# interface ethernet 0/0	Specifies an interface type and number, and places the router in interface configuration mode.
Step 4	ipv6 dhcp client pd {prefix-name | hint ipv6-prefix} [rapid-commit] Example: Router(config-if)# ipv6 dhcp client pd dhcp-prefix	Enables the DHCP for IPv6 client process and enables a request for prefix delegation through a specified interface.

Configuring the DHCP for IPv6 Relay Agent

This task describes how to enable the DHCP for IPv6 relay agent function and specify relay destination addresses on an interface.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 dhcp relay destination ipv6-address [interface-type interface-number]

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	interface type number Example: Router(config)# interface ethernet 4/2	Specifies an interface type and number, and places the router in interface configuration mode.
Step 4	ipv6 dhcp relay destination ipv6-address [interface-type interface-number] Example: Router(config-if) ipv6 dhcp relay destination FE80::250:A2FF:FEBF:A056 ethernet 4/3	Specifies a destination address to which client messages are forwarded and enables DHCP for IPv6 relay service on the interface.

Configuring the Stateless DHCP for IPv6 Function

The following tasks describe how to use the DHCP for IPv6 function to configure clients with information about the name lookup system. The server maintains no state related to clients; for example, no prefix pools and records of allocation are maintained. Therefore, this function is "stateless" DHCP for IPv6.

•Configuring the Stateless DHCP for IPv6 Server

•Configuring the Stateless DHCP for IPv6 Client

•Enabling Processing of Packets with Source Routing Header Options

Configuring the Stateless DHCP for IPv6 Server

The following task describes how to configure the stateless DHCP for IPv6 server.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp pool poolname

4. dns-server ipv6-address

5. domain-name domain

6. exit

7. interface type number

8. ipv6 dhcp server poolname [rapid-commit] [preference value] [allow-hint]

9. ipv6 nd other-config-flag

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp pool poolname Example: Router(config)# ipv6 dhcp pool dhcp-pool	Configures a DHCP for IPv6 configuration information pool and enters DHCP for IPv6 pool configuration mode.
Step 4	dns-server ipv6-address Example: Router(config-dhcp) dns-server 2001:0DB8:3000:3000::42	Specifies the DNS IPv6 servers available to a DHCP for IPv6 client.
Step 5	domain-name domain Example: Router(config-dhcp)# domain-name domain1.com	Configures a domain name for a DHCP for IPv6 client.
Step 6	exit Example: Router(config-dhcp)# exit	Exits DHCP for IPv6 pool configuration mode configuration mode, and returns the router to global configuration mode.
Step 7	interface type number Example: Router(config)# interface serial 3	Specifies an interface type and number, and places the router in interface configuration mode.
Step 8	ipv6 dhcp server poolname [rapid-commit] [preference value] [allow-hint] Example: Router(config-if)# ipv6 dhcp server dhcp-pool	Enables DHCP for IPv6 on an interface.
Step 9	ipv6 nd other-config-flag Example: Router(config-if)# ipv6 nd other-config-flag	Sets the "other stateful configuration" flag in IPv6 RAs.

Configuring the Stateless DHCP for IPv6 Client

The following task describes how to configure the stateless DHCP for IPv6 client.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 address autoconfig [default]

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	interface type number Example: Router(config)# interface serial 3	Specifies an interface type and number, and places the router in interface configuration mode.
Step 4	ipv6 address autoconfig [default] Example: Router(config-if)# ipv6 address autoconfig	Enables automatic configuration of IPv6 addresses using stateless autoconfiguration on an interface and enables IPv6 processing on the interface.

Enabling Processing of Packets with Source Routing Header Options

The following task describes how to enable the processing of packets with source routing header options.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 source-route

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 source-route Example: Router(config)# ipv6 source-route	Enables processing of the IPv6 type 0 routing header.

Configuring the DHCP for IPv6 Server Options

The following tasks describe how to configure stateless options on a DHCP for IPv6 server and import those options to a DHCP for IPv6 client:

•Configuring the Information Refresh Server Option

•Importing the Information Refresh Server Option

•Configuring NIS- and NISP-Related Server Options

•Importing NIS- and NIS+-Related Server Options

•Importing SIP Server Options

•Configuring the SNTP Server Option

•Importing Other Stateless DHCP for IPv6 Server Options

Configuring the Information Refresh Server Option

The following task describes how to configure the information refresh server option.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp pool poolname

4. information refresh {days [hours minutes] | infinity}

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp pool poolname Example: Router(config)# ipv6 dhcp pool pool1	Configures a DHCP for IPv6 configuration information pool and enters DHCP for IPv6 pool configuration mode.
Step 4	information refresh {days [hours minutes] | infinity} Example: Router(config-dhcp)# information refresh 1 1 1	Specifies the information refresh time to be sent to the client.

Importing the Information Refresh Server Option

The following task describes how to import the information refresh server option to the DHCP for IPv6 client.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp pool poolname

4. import information refresh

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp pool poolname Example: Router(config)# ipv6 dhcp pool pool1	Configures a DHCP for IPv6 configuration information pool and enters DHCP for IPv6 pool configuration mode.
Step 4	import information refresh Example: Router(config-dhcp)# import information refresh	Imports the information refresh time option to a DHCP for IPv6 client.

Configuring NIS- and NISP-Related Server Options

The following task describes how to configure NIS- and NIS+-related server options.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp pool poolname

4. nis address ipv6-address

5. nis domain-name domain-name

6. nisp address ipv6-address

7. nisp domain-name domain-name

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp pool poolname Example: Router(config)# ipv6 dhcp pool pool1	Configures a DHCP for IPv6 configuration information pool and enters DHCP for IPv6 pool configuration mode.
Step 4	nis address ipv6-address Example: Router(config-dhcp)# nis address 2001:0DB8:1000:1000::30	Specifies the NIS address of an IPv6 server to be sent to the client.
Step 5	nis domain-name domain-name Example: Router(config-dhcp)# nis domain-name domain1	Enables a server to convey a client's NIS domain name information to the client.
Step 6	nisp address ipv6-address Example: Router(config-dhcp)# nisp address 2001:0DB8:3000:3000::42	Specifies the NIS+ address of an IPv6 server to be sent to the DHCP for IPv6 client.
Step 7	nisp domain-name domain-name Example: Router(config-dhcp)# nisp domain-name domain2	Enables a server to convey a client's NIS+ domain name information to the DHCP for IPv6 client.

Importing NIS- and NIS+-Related Server Options

The following task describes how to import NIS- and NIS+-related server options.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp pool poolname

4. import nis address

5. import nis domain-name

6. import nisp address

7. import nisp domain-name

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp pool poolname Example: Router(config)# ipv6 dhcp pool pool1	Configures a DHCP for IPv6 configuration information pool and enters DHCP for IPv6 pool configuration mode.
Step 4	import nis address Example: Router(config-dhcp)# import nis address	Imports the NIS servers option to a DHCP for IPv6 client.
Step 5	import nis domain-name Example: Router(config-dhcp)# import nis domain-name	Imports the NIS domain name option to a DHCP for IPv6 client.
Step 6	import nisp address Example: Router(config-dhcp)# import nisp address	Imports the NISP address option to a DHCP for IPv6 client.
Step 7	import nisp domain-name Example: Router(config-dhcp)# import nisp domain-name	Imports the NISP domain name option to a DHCP for IPv6 client.

Importing SIP Server Options

The following task describes how to import SIP server options to the outbound SIP proxy server.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp pool poolname

4. import sip address

5. import sip domain-name

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp pool poolname Example: Router(config)# ipv6 dhcp pool pool1	Configures a DHCP for IPv6 configuration information pool and enters DHCP for IPv6 pool configuration mode.
Step 4	import sip address Example: Router(config-dhcp)# import sip address	Imports the SIP server IPv6 address list option to the outbound SIP proxy server.
Step 5	import sip domain-name Example: Router(config-dhcp)# import sip domain-name	Imports a SIP server domain-name list option to the outbound SIP proxy server.

Configuring the SNTP Server Option

The following task describes how to configure the SNTP server option.

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 dhcp pool poolname

4. sntp address ipv6-address

5. import sntp address ipv6-address

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ipv6 dhcp pool poolname Example: Router(config)# ipv6 dhcp pool pool1	Configures a DHCP for IPv6 configuration information pool and enters DHCP for IPv6 pool configuration mode.
Step 4	sntp address ipv6-address Example: Router(config-dhcp)# sntp address 2001:0DB8:2000:2000::33	Specifies the SNTP server list to be sent to the client.
Step 5	import sntp address ipv6-address Example: Router(config-dhcp)# im