Re: About IPv6 private address

[Nathan Ward <v6ops@daork.net>]

On 4/02/2008, at 3:59 PM, blue wrote:

> Hi,
>
> I want to ask if there's any reserved private IPv6 address? I know  
> RFC4193 has defined Unique Local IPv6 Unicast Addresses, which is  
> used to replace deprecated site-local address. However, in user's  
> perspective, a device will need a well-known address, such as  
> 192.168.1.1 in IPv4, for a customer to connect to without any  
> configuration. In RFC 4193, the address' "global ID" is generated  
> randomly, and the address could not be known in advance.
>
> After examing all the special purposed IPv6 address, I could not  
> find one for this kind of purpose.

My opinions;

Longer term, it seems as though applications should support link local  
addresses. Has there been any documentation that disagrees with that?  
Safari reports link local addresses with the interface specified as  
being invalid (ie. %en1 at the end = 'invalid').

Shorter term, having a vendor-specific (i.e. manufacturer-, or perhaps  
ISP-) ULA would be a passable idea. As the last 64bits are known from  
the MAC address, and most small hardware devices have their MAC  
printed on them, it should only be a small change to the printing  
process to add either the entire address, or just the trailing 64 bits.

Doing mDNS and things sounds like a nice idea, but if you want it to  
be reliable you'd have to make sure your "install" CD included an mDNS  
client, etc. (I suspect Apple do this for Windows users of their  
airport base stations.). Some problems that I have thought of off the  
top of my head:
- What happens when there are two devices of the same model on the  
link? Does that mean each has to have a unique number in the name?  
(Apple airport things use part of the MAC address for the initial  
name, but, this does not need to be typed by the user as is being  
suggested here..)
- I'm sure I had more problems in my head a few minutes ago.

--
Nathan Ward