using ULA for 'hidden' v6 devices?

Jay Ford jay-ford at
Wed Jan 25 16:11:00 UTC 2012

On Wed, 25 Jan 2012, Justin M. Streiner wrote:
> 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.

Yep.  It works great for strictly local devices which don't need Internet 

Jay Ford, Network Engineering Group, Information Technology Services
University of Iowa, Iowa City, IA 52242
email: jay-ford at, phone: 319-335-5555, fax: 319-335-2951

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