There's nothing unusual about the setup you're asking about - The fact that you're using a tunnel broker doesn't change anything. You need to get an IPv6 network allocation from somewhere (your tunnel broker or your ISP - if you need a tunnel broker and don't have one yet Google can find you a dozen or more), and configure your firewall to handle the IPv6 traffic.

Free IPv4 to IPv6 Tunnel Brokers - LinuxReviews Ideally you want to ping the tunnel brokers IPv6 tunnel point and find out how long it takes for a package to get back and forth; this delay will be added to every IPv6 packet - so you want it as small as possible. The closest tunnel broker (less ping to their POP) is generally the best choice. Check your ISP before creating a tunnel Free IPv6 Tunnels – DNS LookUP That’s right, you can set up your very own Tunnel without going through a tunnel broker if you dare. Be warned, that it is a bit harder to set up than the average IPv6 tunnel so be prepared. You can start by getting a Xem VM from a provider that gives IPv6 connectivity such as Goscomb Technologies.

Oct 31, 2014

Our free tunnel broker service enables you to reach the IPv6 Internet by tunneling over existing IPv4 connections from your IPv6 enabled host or router to one of our IPv6 routers. To use this service you need to have an IPv6 capable host (IPv6 support is available for most platforms) or router which also has IPv4 (existing Internet) connectivity. List of IPv6 tunnel brokers - Wikipedia

What is Tunnel Broker? Webopedia Definition

HE - Tunnel with a dynamic ip-address May 07, 2011 IP version 6 with Dual-stack using a Tunnel broker 6in4 Dec 03, 2018 Tour & Tunnel Creation - YouTube Aug 22, 2009