[Asrg] IPv6, was NATs and spam

[Douglas Otis]

On Mar 5, 2007, at 8:47 AM, John Levine wrote:

>> Is smtp mail ever likely to switch to IPV6?
>
> Eventually, sure.  Some time in the next decade IANA will allocate  
> the last available /8 to the RIRs, and IPv4 space will get a lot  
> more expensive.
>
> We'll probably start seeing v6-only hosts in Asia first, and people  
> will upgrade depending on the pain level of being unreachable from  
> those places.  Given that most Americans are barely aware that  
> Canada exists, much less countries in Asia, I imagine it'll take a  
> while.  I also expect formal and informal v6 to v4 gateways to  
> spring up, with all of the spammy excitement of any third party  
> gateway.

Although IPv6 is commonly used in Japan, it is typically used for  
internal services.  Indeed IPv6 to IPv4 gateways will become  
problematic, as will any other large NAT.  Looking to see the  
durations of a route offers clues.  Identifying those managing the  
routing helps in recognizing different paradigms and what is involved.

> Most network equipment shipped these days can handle v6, so when  
> you finally switch over, it's just going to be a config change.

Defensive practices valid for IPv4 are unlikely to remain a viable  
strategy within a predominate IPv6 environment.  Many security  
related strategies are likely to need rethinking.  IPv6 will not  
solve black-hole listing problems, or remove problems associated with  
NATs, unless dependence upon the IP address is replaced with  
dependence upon a CA Cert perhaps.

-Doug