DHCPv6

You can use DHCP with IPv6 using the CLI. To configure DHCP, ensure IPv6 is enabled by going to System > Feature Visibility and enabling IPv6.

Use the CLI command

config system dhcp6

For more information on the configuration options, see the FortiGate CLI Reference.

DHCP delegated mode

Downstream IPv6 interfaces can receive address assignments on delegated subnets from a DHCP server that serves an upstream interface.

DHCPv6-PD configuration

Enable DHCPv6 Prefix Delegation on upstream interface (port10):

config system interface
   edit "port10"
     config ipv6
       set dhcp6-prefix-delegation enable
     end
   end

Assign delegated prefix on downstream interface (port1). Optionally, specific delegated prefixes can be specified:

config system interface
  edit "port1"
    config ipv6
      set ip6-mode delegated
      set ip6-upstream-interface "port10"
      set ip6-subnet ::1:0:0:0:1/64
      set ip6-send-adv enable
      config ipv6-delegated-prefix-list
        edit 1
          set upstream-interface "port10"
          set autonomous-flag enable
          set onlink-flag enable
          set subnet 0:0:0:100::/64
        end
      end
    end
			

DHCPv6 server configuration

Configuring a server that uses delegated prefix and DNS from upstream:

config system dhcp6 server
   edit 1
     set dns-service delegated
     set interface "wan2"
     set upstream-interface "wan1"
     set ip-mode delegated
     set subnet 0:0:0:102::/64
   end

DHCPv6 relay

You can use the following command to configure a FortiGate interface to relay DHCPv6 queries and responses from one network to a network with a DHCPv6 server and back. The command enables DHCPv6 relay and includes adding the IPv6 address of the DHCP server that the FortiGate unit relays DHCPv6 requests to:

config system interface

edit internal

config ipv6

set dhcp6-relay-service enable

set dhcp6-relay-type regular

set dhcp6-relay-ip 2001:db8:0:2::30

end

Optaining IPv6 IP addresses from a DHCP server

From the CLI, you can configure any FortiGate interface to get an IPv6 address from an IPv6 DHCP server. For example, to configure the wan2 interface to get an IPv6 address from an IPv6 DHCP server enter the following command:

config system interface

edit wan2

config ipv6

set ip6-mode dhcp

end