[Re: http://tools.ietf.org/search/draft-hain-ipv6-ulac-01]

Owen DeLong owen at delong.com
Thu Apr 29 16:23:37 UTC 2010


On Apr 29, 2010, at 8:45 AM, Bill Stewart wrote:

> On Mon, Apr 26, 2010 at 7:20 AM, Stephen Sprunk <stephen at sprunk.org> wrote:
> 
>> The vast majority of residential customers have a single subnet, so they
>> can get by just fine using IPv6 link-local addresses.  The vanishingly
>> small percentage that have multiple subnets are presumably savvy enough
>> to set up ULA-R addresses.  There is no need for ULA-C in this scenario.
> 
> Actually it's pretty common for residential customers to have multiple subnets,
> one wired and one wireless, even if they're both NAT'd to 192.168.x.x.
> They may may or not be doing anything with the wired subnet,
> and their wireless router may also be providing a wired subnet bridged
> with the wireless,

If it's bridged, they are not separate subnets. This is the most common configuration.
For one thing, if they are both NAT'd, things on wireless the consumer expects to
be able to talk to things on wired tend not to work. (This is only partially due to
NAT, but, largely due to lazy code that assumes everything is on one subnet
which is usually a safe assumption. The reason this became a usually safe
assumption is another example of damage done by NAT).

> and it's all happening in little consumer-appliance boxes that work by magic,
> but it's out there.
> 

Not quite the way you seem to think it is.

Owen





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