Re: [v6ops] RFC 7084 on Basic Requirements for IPv6 Customer Edge Routers

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> De : Wuyts Carl <[e-mail]>
> Indeed, this will not be always known upfront. 

Carl, could you please give an example where a router doesn't know 
upfront the number of interfaces? Even if some of them could be 
off at some point (Wifi for example), the router usually knows 
the maximum number of local interfaces it can support. 

> Besides that, if you
> purely want to look at all active interfaces, I believe you will be 
> (for residential market at least) push for a /64 for all 
> deployments, and I don?t believe this should be the goal.  After 
> all, many residential scenario?s at our customer base are a single 
> LAN from defs?.

I don't see why this would push /64 in the residential market. 
Most recent routers are expected to have a few interfaces (one 
for public wifi and another for the private lan for example) and 
therefore should hint for a /60 at least. If DHCPv6-PD is supported 
on the LAN side, a hint for /56 or /48 would be expected. 

And a hint is just that, a hint. The operator is free to hand out
larger prefixes. Some operators will hand out a /64 in the 
absence of a hint because of a number of broken old implementations
unable to carve out /64s out of larger prefixes. But beside these, 
/56 or larger is expected to become the standard for residential. 

As a data point, we hand out /56s by default as a cable 
operator and it works fairly well so far. 

/JF