Hurricane Electric's IPv6 Tunnel Broker Forums

Tunnelbroker.net Specific Topics => Questions & Answers => Topic started by: mbunkus on April 20, 2011, 06:20:36 AM

Title: "Unable to find a unique /48" when trying to create a routed subnet
Post by: mbunkus on April 20, 2011, 06:20:36 AM
So far my tunnel only had a routed /64 (default after having created a tunnel). Today I wanted to allocate a /48 as well, clicked on the link and received the following error:

Code: [Select]
unable to find a unique /48
Is this a permanent error? Do I have to create a new tunnel? Am I doing something wrong? :)
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: cholzhauer on April 20, 2011, 06:21:50 AM
Which tunnel server are you using?  I know at one time they were unable to allocate more /48's from a certain few servers

You'd do best to email ipv6@he.net and alert them to your error
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: mbunkus on April 20, 2011, 06:25:42 AM
The one in Frankfurt. Thanks for the hint. I'll email them.
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: mbunkus on April 20, 2011, 11:57:01 PM
For reference, here's HE's reply:

Code: [Select]
This tunnel server is currently out of /48s to assign to users. 
We are working on providing more /48s to users but no ETA at this time.

You are welcome to try other tunnel servers.
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: Krellan on May 08, 2011, 09:35:32 PM
For reference, here's HE's reply:

Code: [Select]
This tunnel server is currently out of /48s to assign to users. 
We are working on providing more /48s to users but no ETA at this time.

You are welcome to try other tunnel servers.

Not good, IPv6 is running out of address space!

Better wait for IPv7 :)

Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: tomuk5 on June 23, 2011, 11:56:03 AM
iv had the same message tonight

Code: [Select]
Error: Unable to find a unique /48
when connecting to the london server and applying for a /48 subnet
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: johnpoz on June 23, 2011, 12:34:17 PM
Quote
Not good, IPv6 is running out of address space!

I'm sure you meant that as a joke and its funny and all ;)  But on a serious note -- I personally do not understand the need of giving out even /64 to anyone..  come on..  This is what is planned to be handed out to users -- 18,446,744,073,709,551,616 addresses, come on.. Did we learn nothing from how IPv4 was handled.  with a /48 your talking 64,000 x 18,446,744,073,709,551,616 for possible addresses..

Yes I understand the address space for IPv6 "seems" infinitely large, but improperly managed and you can run out of anything..  What possible reason could there be that a lan would need a /64??

I just don't understand their logic with /64 being the breaking spot for addresses.  Its pure insanity if you ask me.
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: Azendale on June 24, 2011, 03:49:16 PM
The main reason people use a /64 for a LAN is that is the minimum for autoconf. If all you machines are DHCPv6 capable, you can set a smaller range like a /112 and use DHCPv6 to automatically give out addresses in that range instead of autoconf.

It does seem like a lot of space. If my math is correct, then IPv6 /120 = IPv4 /24 and 72,057,594,037,927,936 x IPv4 /24 = IPv6 /64.

My theory for why so many addresses is this: People will switch to IPv6 and use autoconf. That will force much 'extra' space to be allocated. Then when people want to get more fancy with their home network setup (more equipment, more hierarchy, everything electronic IPv6 enabled) they'll switch to DHCPv6 instead of asking for more addresses. That will avoid people having to readdress everything. We wouldn't want NAT introduced to IPv6 in the future because it's easier to set up NAT than to get more addresses ard readdress everything.
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: jrocha on June 24, 2011, 04:06:03 PM
Quote
Not good, IPv6 is running out of address space!

I'm sure you meant that as a joke and its funny and all ;)  But on a serious note -- I personally do not understand the need of giving out even /64 to anyone..  come on..  This is what is planned to be handed out to users -- 18,446,744,073,709,551,616 addresses, come on.. Did we learn nothing from how IPv4 was handled.  with a /48 your talking 64,000 x 18,446,744,073,709,551,616 for possible addresses..

Yes I understand the address space for IPv6 "seems" infinitely large, but improperly managed and you can run out of anything..  What possible reason could there be that a lan would need a /64??

I just don't understand their logic with /64 being the breaking spot for addresses.  Its pure insanity if you ask me.

The main idea behind /64 for SLAAC is that it uses EUI-64 for choosing interface addresses. Remember, it is based on the 48bit MAC address.

Also, don't think of IPv6 prefixes in terms of address space. You should think of it in terms of subnet space. If you are using SLAAC, then a /64 only gives you a single LAN segment. With a /48 (or /56), you can subnet out into a more complicated network layout.
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: snarked on June 25, 2011, 01:20:53 AM
Which means that the subnet of choice should have been "/80."
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: kcochran on June 25, 2011, 04:24:49 AM
Except that there are some devices using 64bit addressing, such as Firewire.  Ethernet may be almost everywhere, but it's not ubiquitous.  They left in room for growth on that side of things too.
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: snarked on June 25, 2011, 04:25:17 PM
I know of no one who routes anything over firewire.  It's for devices, not host-host communication.
Title: Re: "Unable to find a unique /48" when trying to create a routed subnet
Post by: jrocha on June 25, 2011, 04:37:42 PM
I know of no one who routes anything over firewire.  It's for devices, not host-host communication.

I've seen a couple of devices that do IP over firewire, but granted, it isn't very common. See http://tools.ietf.org/html/rfc2734 (http://tools.ietf.org/html/rfc2734) and http://tools.ietf.org/html/rfc3146 (http://tools.ietf.org/html/rfc3146)

If that doesn't convince you, then think about the fact that one day MAC addressing might have to be expanded to 64bits, or replaced with something longer. (MACv6 anyone?)