using ULA for 'hidden' v6 devices?

Cameron Byrne cb.list6 at
Wed Jan 25 16:06:08 UTC 2012

On Jan 25, 2012 7:52 AM, "Justin M. Streiner" <streiner at>
> Is anyone using ULA (RFC 4193) address space for v6 infrastructure that
does not need to be exposed to the outside world?  I understand the concept
of having fc00::/8 being doled out by the RIRs never went anywhere, and
using space out of fd00::/8 can be a bit of a crap-shoot because of the
likelihood of many organizations that do so not following the algorithm for
picking a /48 that is outlined in the RFC.
> There would appear to be reasonable arguments for and against using ULA.
I'm just curious about what people are doing in practice.

Yes. Uses may include the DNS  interface that you only want your customers
to query.... or pretty much any service, as you said, that does not need to
be connected to the internet.

Beware of ULA haters.


> jms

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