IPv6 for generic DSL dialup

Introduction

This short article shows how to setup IPv6 on a standard DSL connection and how to handover the delegated prefix from your provider in your local LAN.

It’s compatible and tested for but not limited to:

  • Deutsche Telekom

Step 1 - General Settings

Go to System ‣ Settings ‣ General and check that Prefer IPv4 over IPv6 is not ticked. This value is default so just check if it has been touched.

Also enable Allow DNS server list to be overridden by DHCP/PPP on WAN at the bottom, so you get the correct DNS servers if you just use IPv4 ones.

Step 2 - Allow IPv6

Next go to Interfaces ‣ Settings and verify that Turn off IPv6 is disabled.

Step 3 - Interface Configuration

Go to Interfaces ‣ Assignments, edit WAN, set IPv6 Configuration Type to DHCPv6 and select:

  • Request prefix only

  • Send prefix hint

Set the prefix size to the one your provider delegates, mostly /56 or 64, sometimes /48.

Then edit LAN on the Assignments page and set IPv6 Configuration Type to Track Interface (legacy). Choose WAN as the Parent interface; 0x0 is a valid Assign prefix ID.

Hit Apply and disable/enable the NICs of your internal systems. Depending on the system and vendor, also a reboot could be required.

If you experience problems with the 24h disconnect disrupting connectivity, it may help to set Prevent Release in section Interfaces ‣ Settings.