Unique Local Addresses

Unique Local Addresses are IPv6 addresses used exclusively for communication within local networks. Packets whose receiving addresses are from the range of unique local addresses are not routed to the Internet. At present unique local addresses are designated by the prefix "fd".

If no IPv6 Internet connection is active, the network devices in your home network do not have assign unique local addresses (ULA), which limits their communication with each other. In this case the FRITZ!Box can assign Unique Local Addresses to the network devices.

• Assign unique local addresses (ULA) as long as no IPv6 connection exists (recommended)

  The FRITZ!Box assigns a ULA to the network devices, as long as no IPv6 Internet connection is active.

• Do not assign unique local addresses (ULA) (not recommended)

  The FRITZ!Box does not assign any ULAs to the network devices. If no IPv6 Internet connection is active, then the network devices cannot communicate with each other.

• Always assign unique local addresses (ULA)

  The network devices always receive their ULAs from the FRITZ!Box, even if an IPv6 connection is active.

Set ULA prefix manually

If you want to set the ULA prefix yourself manually, you can enter any prefix you like. The prefix must be entered in hexadecimal format and have the prescribed length of 64 bits.

DHCPv6 Servers in the Home Network

Enable DHCPv6 server in the FRITZ!Box for the home network:

The effect of this setting is that the network devices in the home network are assigned IPv6 settings from the DHCPv6 server of the FRITZ!Box. These settings are then used instead of the data in the router advertisement messages. The DNS server, IPv6 prefixes or IPv6 addresses can all be assigned by DHCPv6. Define which IPv6 settings should be assigned by the DHCPv6 server.

• Only assign DNS server

  When this setting is selected, the FRITZ!Box is announced as a DNS server via DHCPv6.

• Assign DNS server and IPv6 prefix (IA_PD)

  This setting has the following effect:

  • The FRITZ!Box is announced as a DNS server by DHCPv6.
  • The IPv6 prefix assigned by the Internet service provider is used to derive IPv6 prefixes, which are transmitted to other downstream routers with their own home networks.
• Assign DNS server, prefix (IA_PD) and IPv6 addresses (IA_NA)

  This setting has the following effect:

  • The FRITZ!Box is announced as a DNS server by DHCPv6.
  • The IPv6 prefix assigned by the Internet service provider is used to derive IPv6 prefixes, which are transmitted to other downstream routers with their own home networks.
  • The network devices in the home network receive their IPv6 addresses from the DHCPv6 server of the FRITZ!Box.

Disable DHCPv6 server in the FRITZ!Box

This setting turns off the DHCP server of the FRITZ!Box.

• There are no other DHCPv6 servers in the home network.

  This setting indicates that there are no DHCPv6 servers in the home network. The M and the O flag in the router advertisement messages of the FRITZ!Box are still disabled.

• Enable the O flag in the router advertisement messages of the FRITZ!Box

  This setting enables the O flag in the router advertisement messages of the FRITZ!Box. The enabled O flag transmits the information that there is a DHCPv6 server in the home network, and that IPv6 settings can be obtained from this server, but not the IPv6 address.

• Enable the M and the O flag in the router advertisement messages of the FRITZ!Box

  This setting enables the M and O flags in the router advertisement messages of the FRITZ!Box. These two enabled flags transmits the information that there is a DHCPv6 server in the home network, from which the IPv6 address and other IPv6 settings can be obtained.