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DHCPv6 Address-Assignment Pools

Address pool is a set of Internet Protocol addresses available for allocation to users, such as in host configurations with the DHCP. An address-assignment pool can support either IPv4 address or IPv6 addresses. You cannot use the same pool for both types of address. For more information, read this topic.

Example: Configuring an Address-Assignment Pool for IPv6 Addresses

This example shows how to configure an address-assignment pool on SRX1500, SRX5400, SRX5600, and SRX5800 devices.

Requirements

Before you begin:

  • Specify the name of the address-assignment pool and configure addresses for the pool.

  • Set DHCPv6 attributes for the address-assignment pool.

Overview

In this example, you configure an address-pool called my-pool and specify the IPv6 family as inet6. You configure the IPv6 prefix as 2001:db8:3000:1::/64, the range name as range1, and the IPv6 range for DHCPv6 clients from a low of 2001:db8:3000:1::1/64 to a high of 2001:db8:3000:1::100/64. You can define the range based on the lower and upper boundaries of the prefixes in the range or based on the length of the prefixes in the range. Finally, you specify the DHCPv6 attribute for the DNS server as 2001:db8:3001::1, the grace period as 3600, and the maximum lease time as 120.

Configuration

Procedure

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure an IPv6 address-assignment pool:

  1. Configure an address-pool and specify the IPv6 family.

  2. Configure the IPv6 prefix, the range name, and IPv6 range for DHCPv6 clients.

  3. Configure the DHCPv6 attribute for the DNS server for the address pool.

  4. Configure the DHCPv6 attribute for the grace period.

  5. Configure the DHCPv6 attribute for the maximum lease time.

Results

From configuration mode, confirm your configuration by entering the show access address-assignment command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

If you are done configuring the device, enter commit from configuration mode.

Verification

Verifying Configuration

Purpose

Verify that the address-assignment pool has been configured.

Action

From operational mode, enter the show access address-assignment command.

Configuring a Named Address Range and DHCPv6 Attributes for Dynamic Address Assignment

You can optionally configure multiple named ranges, or subsets of addresses, within an address-assignment pool. During dynamic address assignment, a client can be assigned an address from a specific named range. To create a named range, you specify a name for the range and define the address range and DHCPv6 attributes.

To configure a named address range for dynamic address assignment:

  1. Specify the name of the address-assignment pool and the IPv6 family.
  2. Configure the IPv6 prefix and then define the range name and IPv6 range for DHCPv6 clients. You can define the range based on the lower and upper boundaries of the prefixes in the range, or based on the length of the prefixes in the range.
  3. Configure DHCPv6 attributes for the address pool.
  4. If you are done configuring the device, enter commit from configuration mode.

Configuring an Address-Assignment Pool for Router Advertisement

For SRX1500, SRX5400, SRX5600, and SRX5800 devices, you can create an address-assignment pool that is explicitly used for router advertisement address assignment. You populate the address-assignment pool using the standard procedure, but you additionally specify that the pool is used for router advertisement.

To configure an address-assignment pool that is used for router advertisement:

  1. Create the IPv6 address-assignment pool.
  2. Specify that the address-assignment pool is used for router advertisement.
  3. If you are done configuring the device, enter commit from configuration mode.

Configuring Nontemporary Address Assignment

Nontemporary address assignment is also known as stateful address assignment. In the stateful address assignment mode, the DHCPv6 client requests global addresses from the DHCPv6 server. Based on the DHCPv6 server’s response, the DHCPv6 client assigns the global addresses to interfaces and sets a lease time for all valid responses. When the lease time expires, the DHCPv6 client renews the lease from the DHCPv6 server.

This example is tested on SRX300, SRX320, SRX340, SRX550M, and SRX1500 devices.

To configure nontemporary (stateful) address assignment:

  1. Specify the DHCPv6 client interface.
  2. Configure the client type as statefull.
  3. Specify the IA_NA assignment.

Configuring Identity Associations for Nontemporary Addresses and Prefix Delegation

The DHCPv6 client requests IPv6 addresses and prefixes from the DHCPv6 server. Based on the DHCPv6 server’s response, the DHCPv6 client assigns the IPv6 addresses to interfaces and sets a lease time for all valid responses. When the lease time expires, the DHCPv6 client renews the lease from the DHCPv6 server.

To configure identity association for nontemporary addresses (IA_NA) and identity association for prefix delegation (IA_PD) on SRX300, SRX320, SRX340, SRX550M, and SRX1500 devices:

  1. Specify the DHCPv6 client interface.
  2. Configure the client type as statefull.
  3. Specify the IA_NA.
  4. Specify the IA_PD.

Configuring Auto-Prefix Delegation

You can use DHCPv6 client prefix delegation to automate the delegation of IPv6 prefixes to the customer premises equipment (CPE). With prefix delegation, a delegating router delegates IPv6 prefixes to a requesting router. The requesting router then uses the prefixes to assign global IPv6 addresses to the devices on the subscriber LAN. The requesting router can also assign subnet addresses to subnets on the LAN.

To configure auto-prefix delegation for SRX300, SRX320. SRX340, SRX345, SRX550M, and SRX1500 devices:

  1. Configure the DHCPv6 client type as statefull.
  2. Specify the identity association type as ia-na for nontemporary addresses.
  3. Specify the identity association type as ia-pd for prefix delegation.
  4. Configure the DHCPv6 client identifier by specifying the DUID type.
  5. Specify the interface used to delegate prefixes.

Multiple Address Assignment for DHCPv6 Clients

For a DHCPv6 local server, you can assign multiple addresses to a single DHCPv6 client. Multiple address support is enabled by default, and is activated when the DHCPv6 local server receives a DHCPv6 Solicit message from a DHCP client that contains multiple addresses.

For example, if you are implementing this feature on the routers, you might use the multiple address assignment feature when a customer premises equipment (CPE) device requires a host address and a delegated prefix.

You can use either local address pools or RADIUS when assigning multiple addresses to a DHCP client. When at least one address is successfully allocated, the switch creates a DHCP client entry and binds the entry to the assigned address. If both addresses are successfully allocated, the switch creates a single DHCP client entry and binds both addresses to that entry.

You can also configure a delegated address pool, which explicitly specifies the address pool that DHCP management uses to assign IPv6 prefixes for DHCP clients.