Dynamic IPv6 prefix assignment configuration example

Network requirements

As shown in Figure 96, the router acts as a DHCPv6 server to assign an IPv6 prefix, a DNS server address, a domain name, a SIP server address, and a SIP server name to each DHCPv6 client.

The router assigns prefix 2001:0410:0201::/48 to the client whose DUID is 00030001CA0006A40000, and assigns prefixes in the range of 2001:0410::/48 to 2001:0410:FFFF::/48 (excluding 2001:0410:0201::/48) to other clients. The DNS server address is 2::2:3. The DHCPv6 clients reside in the domain aaa.com. The SIP server address is 2:2::4, and the SIP server name is bbb.com.

Figure 96: Network diagram

Configuration procedure

# Specify an IPv6 address for GigabitEthernet 1/0/1.

<Router> system-view
[Router] interface gigabitethernet 1/0/1
[Router-GigabitEthernet1/0/1] ipv6 address 1::1/64

# Disable RA message suppression on GigabitEthernet 1/0/1.

[Router-GigabitEthernet1/0/1] undo ipv6 nd ra halt

# Set the M flag to 1 in RA advertisements to be sent on GigabitEthernet 1/0/1. Hosts that receive the advertisements will obtain IPv6 addresses through DHCPv6.

[Router-GigabitEthernet1/0/1] ipv6 nd autoconfig managed-address-flag

# Set the O flag to 1 in RA advertisements to be sent on GigabitEthernet 1/0/1. Hosts that receive the advertisements will obtain information other than IPv6 address through DHCPv6.

[Router-GigabitEthernet1/0/1] ipv6 nd autoconfig other-flag
[Router-GigabitEthernet1/0/1] quit

# Create prefix pool 1, and specify the prefix 2001:0410::/32 with assigned prefix length 48.

[Router] ipv6 dhcp prefix-pool 1 prefix 2001:0410::/32 assign-len 48

# Create address pool 1.

[Router] ipv6 dhcp pool 1

# In address pool 1, specify subnet 1::/64 where the server interface resides.

[Router-dhcp6-pool-1] network 1::/64

# Apply prefix pool 1 to address pool 1, and set the preferred lifetime to one day, and the valid lifetime to three days.

[Router-dhcp6-pool-1] prefix-pool 1 preferred-lifetime 86400 valid-lifetime 259200

# In address pool 1, bind prefix 2001:0410:0201::/48 to the client DUID 00030001CA0006A40000, and set the preferred lifetime to one day, and the valid lifetime to three days.

[Router-dhcp6-pool-1] static-bind prefix 2001:0410:0201::/48 duid 00030001CA0006A40000 preferred-lifetime 86400 valid-lifetime 259200

# Configure the DNS server address as 2:2::3.

[Router-dhcp6-pool-1] dns-server 2:2::3

# Configure the domain name as aaa.com.

[Router-dhcp6-pool-1] domain-name aaa.com

# Configure the SIP server address as 2:2::4, and the SIP server name as bbb.com.

[Router-dhcp6-pool-1] sip-server address 2:2::4
[Router-dhcp6-pool-1] sip-server domain-name bbb.com
[Router-dhcp6-pool-1] quit

# Enable the DHCPv6 server on interface GigabitEthernet 1/0/1, enable desired prefix assignment and rapid prefix assignment, and set the preference to the highest.

[Router] interface gigabitethernet 1/0/1
[Router-GigabitEthernet1/0/1] ipv6 dhcp select server
[Router-GigabitEthernet1/0/1] ipv6 dhcp server allow-hint preference 255 rapid-commit

Verifying the configuration

# Display the DHCPv6 server configuration on GigabitEthernet 1/0/1.

[Router-GigabitEthernet1/0/1] display ipv6 dhcp server interface gigabitethernet 1/0/1
Using pool: global
Preference value: 255
Allow-hint: Enabled
Rapid-commit: Enabled

# Display information about address pool 1.

[Router-GigabitEthernet1/0/1] display ipv6 dhcp pool 1
DHCPv6 pool: 1
  Network: 1::/64
    Preferred lifetime 604800, valid lifetime 2592000
  Prefix pool: 1
    Preferred lifetime 86400, valid lifetime 259200
  Static bindings:
    DUID: 00030001ca0006a4
    IAID: Not configured
    Prefix: 2001:410:201::/48
      Preferred lifetime 86400, valid lifetime 259200
  DNS server addresses:
    2:2::3
  Domain name:
    aaa.com
  SIP server addresses:
    2:2::4
  SIP server domain names:
    bbb.com

# Display information about prefix pool 1.

[Router-GigabitEthernet1/0/1] display ipv6 dhcp prefix-pool 1
Prefix: 2001:410::/32
Assigned length: 48
Total prefix number: 65536
Available: 65535
In-use: 0
Static: 1

# After the client with the DUID 00030001CA0006A40000 obtains an IPv6 prefix, display the binding information on the DHCPv6 server.

[Router-GigabitEthernet1/0/1] display ipv6 dhcp server pd-in-use
Pool: 1
 IPv6 prefix                                 Type      Lease expiration
 2001:410:201::/48                           Static(C) Jul 10 19:45:01 2009

# After the other client obtains an IPv6 prefix, display the binding information on the DHCPv6 server.

[Router-GigabitEthernet1/0/1] display ipv6 dhcp server pd-in-use
Pool: 1
 IPv6 prefix                                 Type      Lease expiration
 2001:410:201::/48                           Static(C) Jul 10 19:45:01 2009
 2001:410::/48                               Auto(C)   Jul 10 20:44:05 2009