Glue for exporting DHCP provisioning into Bind
philipp_subx at redfish-solutions.com
Wed Jun 13 18:15:53 UTC 2018
My last message didn’t get any replies so let me try a more tangible question.
I’m looking at this article:
in particular the example.
From the subnet 198.51.100.0/26 for a host they get the following RR’s:
188.8.131.52.in-addr.arpa. 86400 IN CNAME 1.0/184.108.40.206.in-addr.arpa.
1.0/220.127.116.11.in-addr.arpa. 86400 IN PTR my.machine.example.
Dumb question… they end up with 5 octets before they add the suffix on and reverse the order:
How are they deriving those last 2 digits? The 198.51.100 is obvious… that’s 26 rounded down to the nearest multiple of 8 (/24) and taking that many net digits… the /26 is of course the prefix. 0 would be the network start, I guess? Since it’s a /26 prefix, subtracted from 32, that’s 6… 2^6 is 64, so there would be 0, 64, 128, and 256 as subnet starts… And I’m guessing that 1 module 64 is 1… and that’s how they get the 1 digit?
What if the prefix were /22?
More information about the bind-workers