migration revision 9769d3146777ca71af80b459ecec1ef8e2d05950
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonCopyright (C) 2000 Internet Software Consortium.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonSee COPYRIGHT in the source root or http://www.isc.org/copyright for terms.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonBIND 8 to BIND 9 Migration Notes
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonBIND 9 is designed to be mostly upwards compatible with BIND 8, but
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonthere is still a number of caveats you should be aware of when
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonupgrading an existing BIND 8 installation to use BIND 9.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonUnimplemented Options and Changed Defaults
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonSome BIND 8 configuration options are still unimplemented in BIND 9,
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonand the default values of some options have changed. If your
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonnamed.conf file uses an unimplemented option, named will log a warning
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonmessage. A message is also logged about each option whose default has
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonchanged unless the option is set explicitly in named.conf.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonStrict RFC1035 Interpretation of TTLs in Zone Files
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonBIND 8 allowed you to omit all TTLs from a zone file, and used the
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonvalue of the SOA MINTTL field as a default for missing TTL values.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonBIND 9 enforces strict compliance with the RFC1035 and RFC2308 TTL
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonrules. The default TTL is the value specified with the $TTL
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssondirective, or the previous explicit TTL if there is no $TTL directive.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonIf there is no $TTL directive and the first RR in the file does not
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonhave an explicit TTL field, the error message "no TTL specified" is
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonlogged and loading the zone file fails.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonTo avoid problems, use a $TTL directive in each zone file.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonInteroperability Impact of New Query Features
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonBIND 9 uses EDNS0 (RFC2671) to advertise its receive buffer size. It
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonalso sets the AD bit in queries to indicate that it wishes to receive
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonDNSSEC responses (this usage of the AD bit is not yet standard, but
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonhopefully it will be soon).
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonMost older servers that do not support EDNS0 and/or DNSSEC, including
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonall known versions of BIND, will send a FORMERR or NOTIMP response to
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonthese queries. When this happens, BIND 9 will automatically retry the
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonquery without EDNS0 and AD.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonUnfortunately, there exists at least one non-BIND name server
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonimplementation that silently ignores these queries instead of sending
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonan error response. Resolving names in zones where all or most
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssonauthoritative servers use this server will be very slow or fail
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssoncompletely. We have contacted the manufacturer of the name server in
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafssoncase and are trying to resolve the issue with them.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas Gustafsson$Id: migration,v 1.1 2000/06/30 22:44:08 gson Exp $