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

Fri Oct 22 01:55:48 UTC 2010

On 10/21/2010 8:38 PM, Owen DeLong wrote:
> Given the number of times and the distance over which I have seen RFC-1918
> routes propagate, this belief is false to begin with, so, removing this false sense
> of security is not necessarily a bad thing.
>
I don't think it's really a propagation issue. As the ISP, I don't 
actually route RFC-1918 space to my corporate customers, many of which 
maintain static assignments (no routing protocol). While they can leak 
packets out, there will never be a return of packets to them. They view 
this as a feature.The tragedy won't be networks deploying NAT. I'm all 
for allowing you to buy
> a gun, ammunition, and aim at your foot or head as you wish.
>
> The tragedy will be if enough networks do this to hobble development of truly
> useful tools that depend on a NAT-free environment to work.

I think we should respect the different types of networks, and their 
administrative goals. I have customers who manage large educational 
networks. Their engineers have a strong belief in free speech and 
openness. They have very few filters, don't utilize NAT, and have a 
reactionary security policy. I also have corporate customers who run 
extreme nat, don't allow access to social network sites, proxy every 
communication in and out, and generally don't care that they break 90%+ 
of the applications that work over the Internet, especially when it's 
not business related.

That being said, I've seen corporate networks change, altering their 
security policy and the way they do things in order to support 
applications which they desire. So I wouldn't be surprised if a tight 
NAT dwelling network suddenly shifted to routing global addressing to 
meet new applications needs.

Jack