DHCPv6 server

1. Function Overview

The DHCPv6 server function assigns (leases) IPv6 addresses to DHCPv6 clients.
Depending on the option, you can also notify the domain name, DNS server information, etc.

The DHCPv6 server function of this product supports the following operations:

  • Stateless DHCPv6

  • Stateful DHCPv6 (IA_NA)

  • DHCPv6-PD (IA_PD)

In addition, by using the DHCPv6-PD client function and DHCPv6-PD server function of this product, the following are possible:

  • The IPv6 prefix obtained by the DHCPv6-PD client can be divided, and the DHCPv6-PD server function can reallocate the IPv6 prefix to a lower-level DHCPv6 client.

  • The IPv6 prefix obtained by the DHCPv6-PD client can be divided and used for addresses distributed by stateful DHCPv6.

  • DNS and domain information obtained by the DHCPv6-PD client can be distributed as DNS and domain information of the DHCPv6 server.

2. Definition of Terms Used

RA (Router Advertisement : Router Advertisement)

This mechanism automatically sets address information and network settings on the IPv6 network for devices on the network to which the router belongs.
The "M flag" and "O flag" included in the RA notify the DHCPv6 client whether "Stateless DHCPv6" and "Stateful DHCPv6" are available.

Stateless Address Auto-Configuration (SLAAC)

This mechanism automatically generates IPv6 addresses.
The IPv6 device itself generates it using the prefix obtained via RA.

Stateless DHCPv6

This mechanism only provides DHCPv6 options from the DHCPv6 server.
IPv6 addresses are generated using methods such as SLAAC or manual configuration.

Stateful DHCPv6

This mechanism provides both IPv6 addresses and DHCPv6 options from the DHCPv6 server.
You can manage and control the addresses leased by the DHCPv6 server and their lease periods.

DHCPv6-PD (Prefix Delegation)

This mechanism delegates IPv6 prefixes.
The DHCPv6-PD server can assign an IPv6 prefix to a DHCPv6-PD client.
DHCPv6-PD can also distribute DHCPv6 options.

IA_NA

This is synonymous with stateful DHCPv6.

IA_PD

This is synonymous with DHCPv6-PD (Prefix Delegation).

O Flag

This is the information set in the RA.
This flag is set to 1 if stateless DHCPv6 is available.

M Flag

This is the information set in the RA.
This flag is set to 1 if stateful DHCPv6 is available.

3. Function Details

The operating specifications for the DHCPv6 server function are outlined below:

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  1. The DHCPv6 server function of this product can be enabled or disabled for the entire system, as well as for each interface.
    For the DHCPv6 server function to function on an interface, the system-wide setting must be enabled.

    • To configure system-wide settings, use the dhcpv6-server command in global configuration mode.

      • You can enable or disable the entire system by setting enable/disable with the dhcpv6-server command in global configuration mode.

    • To configure settings for each interface, use the dhcpv6-server command in the corresponding interface mode.

      • You can enable the interface settings by specifying the DHCPv6 pool with the dhcpv6-server command in interface mode.

  2. The default settings for the DHCPv6 server function are as follows: (In the initial state, this function is not operating.)

    • System-wide settings: Disabled

    • Interface settings: None

  3. When configuring the DHCPv6 server function settings for an interface, do so for the VLAN interface.

    • Configure the settings by specifying the DHCPv6 pool with the dhcpv6-server command.

    • A global IPv6 address must be configured for the VLAN interface using the ipv6 address command.

      • If only a link-local address is set, the dhcpv6-server command cannot be used.

    • The default setting is none.

    • To assign IPv6 addresses and DHCPv6 options using the DHCPv6 server function, the DHCPv6 pool described below must be configured properly.

    • Up to 32 VLAN interfaces can be configured.

  4. The information to be distributed to DHCPv6 clients is determined by the DHCPv6 pool.

    • Use the dhcpv6 pool command to switch to DHCPv6 mode and create a DHCPv6 pool.

    • You can create up to 64 DHCP pools.

  5. You can configure the following settings for the DHCPv6 pool:

    • Range of IPv6 addresses dynamically assigned to clients

    • Prefix dynamically assigned to PD clients

    • DNS server

    • Domain name for name resolution

    • User-defined DHCPv6 options

  6. The following DHCPv6 pool settings allow you to divide and set IPv6 prefixes obtained by the DHCPv6-PD client function.
    The DHCPv6-PD client function is configured with the ipv6 dhcp client pd command.

    • Range of IPv6 addresses dynamically assigned to clients

    • Prefix dynamically assigned to PD clients

  7. User-defined DHCPv6 options can include:

    • You can define options with the option command.

      Option No. Option Name Mnemonics Available for Commands Option Type

      21

      SIP Servers Domain Name List

      sip_servers_domain_name_list

      Array of strings

      22

      SIP Servers IPv6 Address List

      sip_servers_ipv6_address_list

      Array of IPv6 addresses

      27

      NIS Servers

      nis_servers

      Array of IPv6 addresses

      28

      NIS+ Servers

      nis+_servers

      Array of IPv6 addresses

      29

      NIS Domain Name

      nis_domain_name

      Array of strings

      30

      NIS+ Domain Name

      nis+_domain_name

      Array of strings

      31

      SNTP Servers

      sntp_servers

      Array of IPv6 addresses

      32

      Information Refresh Time

      information_refresh_time

      4-octet integer

      33

      BCMCS Controller Domain Name List

      bcmcs_controller_domain_name_list

      Array of strings

      34

      BCMCS Controller IPv6 Address

      bcmcs_controller_ipv6_address

      Array of IPv6 addresses

4. Related Commands

Related commands are indicated below.
For details on the commands, refer to the Command Reference.

Operations Operating commands

DHCPv6 server function settings (system)

dhcpv6-server

DHCPv6 server function settings (interface)

dhcpv6-server

DHCPv6 pool settings

dhcpv6 pool

Setting the range of dynamically assigned IPv6 addresses

range

Setting the prefix to be dynamically assigned to the PD client

prefix-delegation

Setting the DNS server to notify

dns-server

Setting the domain name for name resolution to notify

domain-name

User-defined DHCPv6 option settings

option

Setting the subnet prefix that identifies the link-address field

link-address

Show DHCPv6 pool information

show dhcpv6 pool

Show IPv6 address assignment information for the DHCPv6 client

show dhcpv6 binding

Displaying DHCPv6 server status

show dhcpv6 server

Deleting lease information on the DHCPv6 server

clear dhcpv6-server lease

5. Examples of Command Execution

5.1. Stateless DHCPv6 Server Configuration

Enable the stateless DHCPv6 server on vlan1.

image

  • The IPv6 address of vlan1 is "2001:db8:1::2/64".

  • SWX notifies the vlan1 network of an RA with the O flag tuned ON.

    • RA notifications are configured using the ipv6 nd send-ra command.

  • The PC uses the RA prefix information option to automatically configure the IPv6 address (SLAAC).

  • Distributing DNS server options from the DHCPv6 server using stateless DHCPv6.

■ Setting Procedure

  1. Set the IPv6 address "2001:db8:1::2/64" for vlan1.

    Yamaha(config)# interface vlan1
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 address 2001:db8:1::2/64 (2)
    1 Enable IPv6
    2 Specify an IPv6 address

  2. Create the DHCPv6 pool “pool_vlan1”.

    Yamaha(config)# dhcpv6 pool pool_vlan1
Yamaha(config-dhcp6)#  (1)
    1 Switch to DHCPv6 mode

  3. Set the DNS server to be notified in the DHCPv6 options as the DHCPv6 pool.

    Yamaha(config-dhcp6)# dns-server 2001:db8:2::100

  4. Activate the DHCPv6 server functions on vlan1.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# interface vlan1 (2)
Yamaha(config-if)# dhcpv6-server pool_vlan1 (3)
    1 Exit DHCPv6 mode
    2 Switch to interface mode vlan1
    3 Set "pool_vlan1" for the DHCPv6 server function of the interface

  5. Activate the DHCPv6 server functions for the entire system.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# dhcpv6-server enable (2)
    1 Exit the interface mode
    2 Enable the DHCPv6 server functions for the entire system

  6. Set vlan1 to notify of RA.

    Yamaha(config)# interface vlan1
Yamaha(config-if)# ipv6 nd other-config-flag (1)
Yamaha(config-if)# ipv6 nd send-ra (2)
    1 Set the O flag for RA
    2 Configure RA transmission

5.2. Stateful DHCPv6 Server Configuration

Enable stateful DHCPv6 server to run on vlan1.

image

  • The IPv6 address of vlan1 is "2001:db8:1::2/64".

  • SWX notifies the vlan1 network of an RA with the M flag turned ON.

    • RA notifications are configured using the ipv6 nd send-ra command.

  • Distributed to PCs in the range "2001:db8:1::dd00 - 2001:db8:1::dd7f".

■ Setting Procedure

  1. Set the IPv6 address "2001:db8:1::2/64" for vlan1.

    Yamaha(config)# interface vlan1
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 address 2001:db8:1::2/64 (2)
    1 Enable IPv6
    2 Specify an IPv6 address

  2. Create the DHCPv6 pool “pool_vlan1”.

    Yamaha(config)# dhcpv6 pool pool_vlan1
Yamaha(config-dhcp6)#  (1)
    1 Switch to DHCPv6 mode

  3. Set the range of addresses to be distributed, "2001:db8:1::dd00 - 2001:db8:1::dd7f" (prefix length: 64), as the DHCPv6 pool.

    Yamaha(config-dhcp6)# range 2001:db8:1::dd00 2001:db8:1::dd7f/64

  4. Set the DNS server to be notified in the DHCPv6 options as the DHCPv6 pool.

    Yamaha(config-dhcp6)# dns-server 2001:db8:2::100

  5. Activate the DHCPv6 server functions on vlan1.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# interface vlan1 (2)
Yamaha(config-if)# dhcpv6-server pool_vlan1 (3)
    1 Exit DHCPv6 mode
    2 Switch to interface mode vlan1
    3 Set "pool_vlan1" for the DHCPv6 server function of the interface

  6. Activate the DHCPv6 server functions for the entire system.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# dhcpv6-server enable (2)
    1 Exit the interface mode
    2 Enable the DHCPv6 server functions for the entire system

  7. Set vlan1 to notify of RA.

    Yamaha(config)# interface vlan1
Yamaha(config-if)# ipv6 nd managed-config-flag (1)
Yamaha(config-if)# ipv6 nd send-ra (2)
    1 Set the M flag in RA
    2 Configure RA transmission

5.3. Stateful DHCPv6 Server Settings: Use in Conjunction with DHCPv6-PD Client Function

Enable stateful DHCPv6 server to run on vlan1.
Used in conjunction with the DHCPv6-PD client function, divide the IPv6 prefix obtained by the DHCPv6-PD client function to set and distribute addresses.

image

  • RT acts as a DHCPv6-PD server.

  • DHCPv6-PD client is running on vlan2.

    • Assume that "2001:db8:1:aa00::/56" was obtained on vlan2 with the prefix name "PD_VLAN2".

  • The IPv6 address of vlan2 is "2001:db8:1:aa00::100/64".

    • Set with the ipv6 address pd command.

  • The IPv6 address of vlan1 is "2001:db8:1:aa10::100/64".

    • Set with the ipv6 address pd command.

  • SWX notifies the vlan1 network of an RA with the M flag turned ON.

    • RA notifications are configured using the ipv6 nd send-ra command.

  • Distributed to PCs in the range "2001:db8:1:aa10::dd00 - 2001:db8:1:aa10::dd7f".

■ Setting Procedure

  1. Enable the DHCPv6-PD client function on vlan2.

    Yamaha(config)# interface vlan2
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 dhcp client pd PD_VLAN2 (2)
    1 Enable IPv6
    2 Enable DHCPv6-PD client function

  2. Set the IPv6 address of vlan2 using the prefix obtained by the DHCPv6-PD client function.

    Yamaha(config)# interface vlan2
Yamaha(config-if)# ipv6 address pd PD_VLAN2 ::100/64 (1)
    1 Set to 2001:db8:1:aa00::100/64

  3. Set the IPv6 address of vlan1 using the prefix obtained by the DHCPv6-PD client function.

    Yamaha(config)# interface vlan1
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 address pd PD_VLAN2 ::10:0:0:0:100/64 (2)
    1 Enable IPv6
    2 Set to 2001:db8:1:aa10::100/64

  4. Create the DHCPv6 pool “pool_vlan1”.

    Yamaha(config)# dhcpv6 pool pool_vlan1
Yamaha(config-dhcp6)#  (1)
    1 Switch to DHCPv6 mode

  5. Set the range of addresses to be distributed as the DHCPv6 pool using the prefix obtained by the DHCPv6-PD client function.

    Yamaha(config-dhcp6)# range PD_VLAN2 ::10:0:0:0:dd00 ::10:0:0:0:dd7f/64 (1)
    1 Set to 2001:db8:1:aa10::dd00 - 2001:db8:1:aa10::dd7f/64

  6. Set the DNS server to be notified in the DHCPv6 options as the DHCPv6 pool.

    Yamaha(config-dhcp6)# dns-server 2001:db8:2::100

  7. Activate the DHCPv6 server functions on vlan1.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# interface vlan1 (2)
Yamaha(config-if)# dhcpv6-server pool_vlan1 (3)
    1 Exit DHCPv6 mode
    2 Switch to interface mode vlan1
    3 Set "pool_vlan1" for the DHCPv6 server function of the interface

  8. Activate the DHCPv6 server functions for the entire system.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# dhcpv6-server enable (2)
    1 Exit the interface mode
    2 Enable the DHCPv6 server functions for the entire system

  9. Set vlan1 to notify of RA.

    Yamaha(config)# interface vlan1
Yamaha(config-if)# ipv6 nd managed-config-flag (1)
Yamaha(config-if)# ipv6 nd send-ra (2)
    1 Set the M flag in RA
    2 Configure RA transmission

5.4. DHCPv6-PD Server Settings

Enable the DHCPv6-PD server to run on vlan1.

image

  • The IPv6 address of vlan1 is "2001:db8::100/48".

  • Configure the settings to divide the subnet prefix "2001:db8::/40" of vlan1 and dynamically allocate prefixes "2001:db8::/48 - 2001:db8:ff::/48".

■ Setting Procedure

  1. Set the IPv6 address "2001:db8::100/48" for vlan1.

    Yamaha(config)# interface vlan1
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 address 2001:db8::100/48 (2)
    1 Enable IPv6
    2 Specify an IPv6 address

  2. Create the DHCPv6 pool “pool_vlan1”.

    Yamaha(config)# dhcpv6 pool pool_vlan1
Yamaha(config-dhcp6)#  (1)
    1 Switch to DHCPv6 mode

  3. Set the prefix to be assigned, "2001:db8::/48 - 2001:db8:ff::/48", as the DHCPv6 pool.

    Yamaha(config-dhcp6)# prefix-delegation 2001:db8::/40 48

  4. Set the DNS server to be notified in the DHCPv6 options as the DHCPv6 pool.

    Yamaha(config-dhcp6)# dns-server 2001:db8:2::100

  5. Activate the DHCPv6 server functions on vlan1.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# interface vlan1 (2)
Yamaha(config-if)# dhcpv6-server pool_vlan1 (3)
    1 Exit DHCPv6 mode
    2 Switch to interface mode vlan1
    3 Set "pool_vlan1" for the DHCPv6 server function of the interface

  6. Activate the DHCPv6 server functions for the entire system.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# dhcpv6-server enable (2)
    1 Exit the interface mode
    2 Enable the DHCPv6 server functions for the entire system

5.5. DHCPv6-PD Server Settings: Use in Conjunction with DHCPv6-PD Client Function

Enable the DHCPv6-PD server to run on vlan1.
Used in conjunction with the DHCPv6-PD client function, divide the IPv6 prefix obtained by the DHCPv6-PD client function to set and distribute prefixes.

image

  • RT acts as a DHCPv6-PD server.

  • DHCPv6-PD client is running on vlan2.

    • Assume that "2001:db8:1:aa00::/56" was obtained on vlan2 with the prefix name "PD_VLAN2".

  • The IPv6 address of vlan2 is "2001:db8:1:aa00::100/64".

    • Set with the ipv6 address pd command.

  • The IPv6 address of vlan1 is "2001:db8:1:aa10::100/64".

    • Set with the ipv6 address pd command.

  • Configure the settings to divide the subnet prefix "2001:db8:1:aa10::/60" of vlan1 and dynamically allocate prefixes "2001:db8:1:aa10::/64 - 2001:db8:1:aa1f::/64".

■ Setting Procedure

  1. Enable the DHCPv6-PD client function on vlan2.

    Yamaha(config)# interface vlan2
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 dhcp client pd PD_VLAN2 (2)
    1 Enable IPv6
    2 Enable DHCPv6-PD client function

  2. Set the IPv6 address of vlan2 using the prefix obtained by the DHCPv6-PD client function.

    Yamaha(config)# interface vlan2
Yamaha(config-if)# ipv6 address pd PD_VLAN2 ::100/64 (1)
    1 Set to 2001:db8:1:aa00::100/64

  3. Set the IPv6 address of vlan1 using the prefix obtained by the DHCPv6-PD client function.

    Yamaha(config)# interface vlan1
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 address pd PD_VLAN2 ::10:0:0:0:100/64 (2)
    1 Enable IPv6
    2 Set to 2001:db8:1:aa10::100/64

  4. Create the DHCPv6 pool “pool_vlan1”.

    Yamaha(config)# dhcpv6 pool pool_vlan1
Yamaha(config-dhcp6)#  (1)
    1 Switch to DHCPv6 mode

  5. Set the prefix to be assigned as the DHCPv6 pool using the prefix obtained by the DHCPv6-PD client function.

    Yamaha(config-dhcp6)# prefix-delegation PD_VLAN2 0:0:0:10::/60 64 (1)
    1 Set to 2001:db8:1:aa10::/64 - 2001:db8:1:aa1f::/64

  6. Set the DNS server to be notified in the DHCPv6 options as the DHCPv6 pool.

    Yamaha(config-dhcp6)# dns-server 2001:db8:2::100

  7. Activate the DHCPv6 server functions on vlan1.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# interface vlan1 (2)
Yamaha(config-if)# dhcpv6-server pool_vlan1 (3)
    1 Exit DHCPv6 mode
    2 Switch to interface mode vlan1
    3 Set "pool_vlan1" for the DHCPv6 server function of the interface

  8. Activate the DHCPv6 server functions for the entire system.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# dhcpv6-server enable (2)
    1 Exit the interface mode
    2 Enable the DHCPv6 server functions for the entire system

5.6. Stateless DHCPv6 Server Configuration: via DHCPv6 Relay Agent

Enable a stateless DHCPv6 server to operate on vlan2 upon DHCPv6 messages relayed by the DHCPv6 relay agent.

image

  • The IPv6 address of vlan2 is "2001:db8:2a::100/64".

  • Distributing DNS server options from the DHCPv6 server using stateless DHCPv6.

  • Use the link-address command to specify the subnet prefix of the IPv6 network to which the DHCPv6 client belongs.

■ Setting Procedure

  1. Set the IPv6 address "2001:db8:2a::100/64" for vlan2.

    Yamaha(config)# interface vlan2
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 address 2001:db8:2a::100/64 (2)
    1 Enable IPv6
    2 Specify an IPv6 address

  2. Create the DHCPv6 pool “pool_vlan2”.

    Yamaha(config)# dhcpv6 pool pool_vlan2
Yamaha(config-dhcp6)#  (1)
    1 Switch to DHCPv6 mode

  3. Set the DNS server to be notified in the DHCPv6 options as the DHCPv6 pool.

    Yamaha(config-dhcp6)# dns-server 2001:db8:2c::100

  4. Use the link-address command to specify the subnet prefix of the IPv6 network to which the DHCPv6 client belongs.

    Yamaha(config-dhcp6)# link-address 2001:db8:2b::/64

  5. Activate the DHCPv6 server functions on vlan2.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# interface vlan2 (2)
Yamaha(config-if)# dhcpv6-server pool_vlan2 (3)
    1 Exit DHCPv6 mode
    2 Switch to interface mode vlan2
    3 Set "pool_vlan2" for the DHCPv6 server function of the interface

  6. Activate the DHCPv6 server functions for the entire system.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# dhcpv6-server enable (2)
    1 Exit the interface mode
    2 Enable the DHCPv6 server functions for the entire system

5.7. Stateful DHCPv6 Server Configuration via DHCPv6 Relay Agent

Enable a stateful DHCPv6 server to operate on vlan2 upon DHCPv6 messages relayed by the DHCPv6 relay agent.

image

  • The IPv6 address of vlan2 is "2001:db8:2a::100/64".

  • Distributed to PCs in the range "2001:db8:2b::dd00 - 2001:db8:2b::dd7f".

■ Setting Procedure

  1. Set the IPv6 address "2001:db8:2a::100/64" for vlan2.

    Yamaha(config)# interface vlan2
Yamaha(config-if)# ipv6 enable (1)
Yamaha(config-if)# ipv6 address 2001:db8:2a::100/64 (2)
    1 Enable IPv6
    2 Specify an IPv6 address

  2. Create the DHCPv6 pool “pool_vlan2”.

    Yamaha(config)# dhcpv6 pool pool_vlan2
Yamaha(config-dhcp6)#  (1)
    1 Switch to DHCPv6 mode

  3. Set the range of addresses to be distributed, "2001:db8:2b::dd00 - 2001:db8:2b::dd7f" (prefix length 64), as the DHCPv6 pool.

    Yamaha(config-dhcp6)# range 2001:db8:2b::dd00 2001:db8:2b::dd7f/64

  4. Set the DNS server to be notified in the DHCPv6 options as the DHCPv6 pool.

    Yamaha(config-dhcp6)# dns-server 2001:db8:2c::100

  5. Activate the DHCPv6 server functions on vlan2.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# interface vlan2 (2)
Yamaha(config-if)# dhcpv6-server pool_vlan2 (3)
    1 Exit DHCPv6 mode
    2 Switch to interface mode vlan2
    3 Set "pool_vlan2" for the DHCPv6 server function of the interface

  6. Activate the DHCPv6 server functions for the entire system.

    Yamaha(config-dhcp6)# exit (1)
Yamaha(config)# dhcpv6-server enable (2)
    1 Exit the interface mode
    2 Enable the DHCPv6 server functions for the entire system

6. Points of Caution

  • Ensure that the IPv6 address of the VLAN interface where the dhcpv6-server command is configured matches the subnet prefix of the IPv6 addresses in the pool specified by the dhcpv6-server command on its VLAN interface.

    • When receiving a DHCPv6 message relayed by a DHCPv6 relay agent, it does not matter if a different subnet prefix is set.

  • When receiving a DHCPv6 message relayed by a DHCPv6 relay agent, configure a pool using the dhcpv6-server command for the VLAN interface that receives the messages.

    • At this point, ensure that the subnet prefix of the IPv6 address in the pool matches the subnet prefix of the IPv6 network to which the DHCPv6 client belongs.

    • At this point, ensure that the IPv6 address of the VLAN interface and the subnet prefix of the IPv6 network to which the DHCPv6 client belongs are different.

7. Related Documentation

None