dhcpcd-discuss

Hi Robert

On 21/06/2014 0:50, Robert White wrote:
> Howdy,
>
> So Comcast will give out three kinds of addresses. If you do an ia_na
> you'll get a ::/128 address. If you do an ia_pd you'll get a ::64
> address by default. And ...
>
> If you do an ia_pd and "ask for one" (electronically) you'll get a
> ::/60 with four bits for your internal subnets. [I know /60 is the
> magic number but I don't know if you can get other values between /60
> and /64.]
>
> I can not figure out how to "ask for one" using dhcpcd. Apparently
> "wide-dhcp" (or some name like that) will format a request with the
> necessary preferred prefix length because of being able to set an
> sla_len or something.
>
> I see some syntactic definitions for IAPREFIX but, if it _is_ in-place
> and functional, I can't figure out how to make one and attach it to
> the ia_pd.


dhcpcd does not support requesting a PD length at this time.
Should be fairly easy to add though


> I would have _expected_ some syntax like:
>
> ia_pd 7/4 int0 int1 # not currently valid syntax
>
> or
>
> ia_pd 7 int0/1/1 int1/2/3 # currently valid syntax
>
> to "shave off" the largest prefix supplied (e.g. four (4) in example
> 1, or three(3) in example two) from the request so that the request
> would go out for a prefix with the shaved value (e.g. ::/60 in example
> one, or ::/61 in example two) such that the sum of the request length
> and the largest specified prefix is 64.
>
> ALTERNATELY... adding an (optional) explicit term with the actual
> desired prefix length might be better.
>
> ia_pd ::/48 (rest of syntax here)
>
> --- So am I missing something or is the feature nonexistent?

We won't be able to "shave off" as such. What we can do is request a 
length
and then "add to" for each int assignment to make your desired prefix 
length
per interface, defaulting to 64.

I think I'll go like so

id_pd 7/::/60 (rest of syntax here)
id_pd ::/60 (rest of syntax here)
id_pd /::/60 (rest of syntax here)

Of course, there is no guarantee you'll get a /60 from the server.

Hopefully I'll be able to add this over the weekend.

Thanks

Roy