this is esp. useful for v6 hosts, where your provider might give you a changing prefix (we assume /64), but your interface ids stay the same.
but same mechanism also principally works for v4 (we assume /29), except that you usually do not get a v4 network where the network address is changing.
and when it comes to dynamic addresses, many people only get 1 ipv4 address anyway. the related host could then be used for aliaseses with ifid == 0 for all aliases.
SSL is the old/outdated name. Since 1999, it's called TLS.
Changed model field names. Added a schema migration to rename the DB columns.
Note: the schema migration also adds/removes the index introduced in cs 32289ebb183907e8618ff251dd5846fd00fe9423
there is an issue with south and sqlite - it doesn't handle migrations that add BooleanField columns with defaults.
just use the faults script to set the flags to their correct default after migrating with south.
"public" field means that this zone can be used by every user (not just the owner) to create hosts there
"available" field means that the nameserver is operating and reachable
if a nameserver does not respond, we flag it in the database
(available = False) and stop talking to it for 5 minutes.
after 5 minutes, we flag it available = True again and retry talking to it
(and if not successful, flag it as unavailable again).
this avoids a unresponsive UI as we do a lot of ns queries from the templates
to get v4 and v6 addresses of our hosts from master nameservers.
we log a warning when setting unavailable and a info when setting available.
