IPv6 fc00::/7 — Unique local addresses

Graham Beneke graham at apolix.co.za
Thu Oct 21 04:30:08 UTC 2010


On 21/10/2010 02:41, Owen DeLong wrote:
> On Oct 20, 2010, at 5:21 PM, Jeroen van Aart wrote:
>> Someone advised me to use GUA instead of ULA. But since for my purposes this is used for an IPv6 LAN would ULA not be the better choice?
>>
> IMHO, no. There's no disadvantage to using GUA and I personally don't think ULA really serves a purpose. If you want to later connect this
> LAN to the internet or something that connects to something that connects to something that connects to the internet or whatever, GUA provides
> the following advantages:
> 	+	Guaranteed uniqueness (not just statistically probable uniqueness)
> 	+	You can route it if you later desire to
>
> Since ULA offers no real advantages, I don't really see the point.

Someone insisted to me yesterday the RFC1918-like address space was the 
only way to provide a 'friendly' place for people to start their journey 
in playing with IPv6. I think that the idea of real routable IPs on a 
lab network daunts many people.

I've been down the road with ULA a few years back and I have to agree 
with Owen - rather just do it on GUA.

I was adding IPv6 to a fairly large experimental network and started 
using ULA. The local NREN then invited me to peer with them but I 
couldn't announce my ULA to them. They are running a 'public Internet' 
network and have a backbone that will just filter them.

I think that the biggest thing that trips people up is that they think 
that they'll just fix-it-with-NAT to get onto the GUA Internet. Getting 
your own GUA from an RIR isn't tough - rather just do it.

-- 
Graham Beneke




More information about the NANOG mailing list