Re: Why ULA: low collision chance (Was: IPv6 fc00::/7 — Unique local addresses)

Jack Bates jbates at
Thu Oct 21 17:42:47 CDT 2010

  On 10/21/2010 5:27 PM, Joel Jaeggli wrote:
> Announce your gua and then blackhole it and monitor your prefix. you can
> tell if you're leaking. it's generally pretty hard to tell if you're
> leaking rfc 1918 since your advertisement may well work depending on the
> filters of your peers but not very far.

This is always the argument I hear from corporate customers concerning 
wanting NAT. If  mistake is made, the RFC 1918 space isn't routable. 
They often desire the same out of v6 for that reason alone.

I personally could understand the fear of wondering if your stateful 
firewall is properly working and doing it's job and how a simple mistake 
could have disastrous effects that NAT systems usually don't have. ULA 
w/ NAT very well may become the norm.


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