sortlist Arithmetic

[Martin McCormick]

	It turns out the arithmetic works as it does on any acl.  I
failed to put a ; after the } in my large sortlist definition.  This
appears to have been syntactically correct, but it sure changed the
definition.  My thanks for the help.

Martin McCormick

Andris Kalnozols writes:
>According to the BIND docs, "Each top level statement in the sortlist
>must itself be an explicit address match list with one or two elements."
>Your first two examples have three elements and the last example matches
>x.x.0.0 through x.x.255.255 as a source address of the query and will
>prefer an answer not matching x.x.0.0 through x.x.15.255.  This is
>assuming that BIND implicitly supplies a zero octet where necessary
>since x.x./17 is only 16 bits of network for the 17-bit mask.  I think
>it's better to avoid such ambiguities for the human reading your config
>file by supplying the third octet, i.e, x.x.0/17.
>
>I suppose an extra set of braces would combine the three network
>segments into one element:
>
>       sortlist {
>                  { { x.x.0/17; x.x.128/18; x.x.192/19; }; };
>                    --------------------------------------
>       };
>
>Or you can use an ACL to aggregate your multiple address match lists
>into one symbolic element:
>
>acl "ok-networks" { x.x.0/17; x.x.128/18; x.x.192/19; };
>
>       sortlist {
>                  { ok-networks; };
>       };
>
>
>Andris Kalnozols
>
>