From what I understand, TunnelBroker is a service that acts as your ISP and allows you a public IPv6 address pointing directly to your machine even if it is behind a NAT.

From what I don't understand, TunnelBroker claims to give you a free /48 block of IPv6 addresses. That's >65k addresses. How do I use them? The only documentation I found regarding TunnelBroker was setting up a regular tunnel with one IPv6 using sit0. Say I had 65,000 computers, and I wanted each computer to be allocated an IPv6, would it be possible with the block of IPs I was given? Where do I go about doing this?


  • 5
    I'm voting to close this question as off-topic because it's a Basic Customer Support question. Please see the meta post linked above for details on how to proceed if you can edit the post and, if put on Hold, have the Hold reviewed. You can also contact the developer for assistance with their product.
    – Tetsujin
    Mar 1, 2019 at 17:54
  • @Tetsujin: Even though none of the actual reasons explained in that post apply here in the first place? It doesn't look like a "policy" question, and it doesn't look like a company-specific question. It looks like a networking question that happens to mention a company. (We've had so many of those that it's practically a duplicate.)
    – user1686
    Mar 1, 2019 at 17:57
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    @grawity - Ask Different has a better FAQ on this type of question - apple.meta.stackexchange.com/questions/2508/… - but why should we be first-line support for any company's structure? The question shows little research.
    – Tetsujin
    Mar 1, 2019 at 18:01
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    I'm hoping more for an answer relating to how networking with IPv6 works, especially with blocks of addresses, and less related to the service offering this address space. I also believe this answer will fill in the blank for information that is not widely available or easily accessible with IPv6.
    – Monstrum
    Mar 1, 2019 at 18:05
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    Yeah, maybe this question deserves to be closed for lack of research, or possibly as a duplicate.   But I agree with @grawity.   I believe that this close reason — “does not appear to be about computer software or computer hardware …” / “Basic Customer Support” — is inappropriate.   By that logic, all questions about Microsoft Word, Excel, Command Prompt, PowerShell, etc., should be closed because the OP should just go and ask Microsoft (hah!), and all questions about GNU software should be closed because the OP should just go and ask the Free Software Foundation.  … (Cont’d) Mar 8, 2019 at 22:13

1 Answer 1


From what I understand, TunnelBroker is a service that acts as your ISP and allows you a public IPv6 address pointing directly to your machine even if it is behind a NAT.

Well, yes. You can also call it a kind of a VPN, basically. However, the bit about "...even if it is behind a NAT" is somewhat misleading:

  1. These IPv6 tunnels are not meant as a NAT bypass method for individual devices; they're meant to deliver IPv6 connectivity to your router, and from there to the whole LAN at once. (Which indeed works just as if it were provided by your real ISP.)

  2. Once the entire LAN has IPv6 connectivity, there's no "...even if" in that statement anymore. The devices simply aren't behind a NAT in the IPv6 network.

    (NAT is specific to each network protocol, so even though your LAN devices are still behind a NAT in the IPv4 network, they're simultaneously not behind a NAT in IPv6.)

TunnelBroker claims to give you a free /48 block of IPv6 addresses. That's >65k addresses

That's >65k subnets, each having a practically-infinite amount of addresses, due to the full IPv6 address length being 128 bits and the "standard" subnet size being /64.

How do I use them?

You use a router for that. (As mentioned above, either configure the tunnel on a router, or turn the tunnel endpoint into a router if it's capable of it.)

  • The tunnel configuration is the same as before: the device still has its own address (the "Client IPv6 address" from tunnel info), it just additionally receives traffic meant for the extra "routed /48" network.

    You don't need to change the tunnel on your side for this to happen; it's enabled by the ISP (Hurricane) updating the routing table on their endpoint.

    (You can even completely ignore the fact that it's a tunnel; everything works the same way as if you were receiving the IP connectivity over a plain Ethernet cable. The only difference from, say, native ISP-provided IPv6 is that you don't need to use DHCPv6-PD to begin receiving the traffic.)

  • Once the router begins receiving traffic meant for the new network, it gets to decide where to send it further. Usually you start by subdividing the /48 into standard /64-sized subnets, and just assigning one of them to the LAN interface or to some VLAN. For example, if you had 2001:db8:123::/48, start with assigning 2001:db8:123:1::1/64 on your LAN interface.

    (This part is nearly identical to configuring networks in IPv4.)

  • Finally, set up an address auto-configuration service for your LAN. Instead of DHCP, in IPv6 the primary autoconfiguration mechanism is SLAAC, i.e. "Router Advertisements".

  • Besides TunnelBroker (also known as HE.net from the company), chances are that you'll find many tutorials about configuring a router for "6to4" or other services. They all work the same as far as LAN usage is concerned. Here are configuration examples for Mikrotik RouterOS, for Windows XP, for Gentoo Linux, for generic Linux.

  • SixXS shut down years ago.
    – rfc2460
    Mar 8, 2019 at 23:52

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