dhcpcd-discuss

Hi


On 30/05/17 21:01, Harald Albrecht wrote:
> Hi,
>
> anothwr discussion here reminded me of a question I alsways had in my 
> mind about assigning prefixes from a delegated prefix block: is the 
> "SLA" a bitfield that gets added to the delegated prefix or is it an 
> integer that gets added to the prefix (base)?

It's a bitmask. Code here:
https://dev.marples.name/source/dhcpcd/browse/master/src/ipv6.c;f58a7db77fd3dfec7f0d5c3630ecf906f300e9c1$484
> For example, let's ask for a /63 prefix delegation, and the delegating 
> router hands out 2001:db8:0:ff ... for whatever reason, that where it 
> has space for two prefixes. Or is this already an invalid assumption, 
> so delegating routers never allocate on "unaligned" boundaries?

It's an invalid assumption, because anything beyond the prefix mask is 
ours to play with as we choose.

> Would then the second prefix 2001:db8:0:ff::PLUS 0:0:0:1:: or is this 
> wrong, because the prefix block needs to be 2001:db8:0:fe:: OR 0:0:0:1?

Because it's /63 you were really delegated 2001:db8:0:fe

Hope this helps

Roy