migration revision 69b641bf31d95fd79a50dcea2cdb0fcb23fe22c6
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonCopyright (C) 2000 Internet Software Consortium.
9769d3146777ca71af80b459ecec1ef8e2d05950Andreas GustafssonSee COPYRIGHT in the source root or http://www.isc.org/copyright for terms.
69b641bf31d95fd79a50dcea2cdb0fcb23fe22c6David Lawrence BIND 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.
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafsson1. Configuration File Compatibility
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafsson1.1. Unimplemented Options and Changed Defaults
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas GustafssonBIND 9.0.0 supports most, but not all but not of the named.conf
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssonoptions of BIND 8. Unimplemented options include those for selective
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafsson(per-domain) forwarding, sortlists, statistics, and process limits;
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssonfor a complete list, see doc/misc/options. We plan to implement most
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssonof these in in BIND 9.1.
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas GustafssonIf your named.conf file uses an unimplemented option, named will log a
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssonwarning message. A message is also logged about each option whose
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssondefault has changed unless the option is set explicitly in named.conf.
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas GustafssonThe set of logging categories in BIND 9 is different from that
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonin BIND 8. If you have customized your logging on a per-category
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonbasis, you need to modify your logging statement to use the
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonnew categories.
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas GustafssonAnother difference is that the "logging" statement only takes effect
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonafter the entire named.conf file has been read. This means that when
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonthe server starts up, any messages about errors in the configuration
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonfile are always logged to the default destination (syslog) when the
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonserver first starts up, regardless of the contents of the "logging"
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonstatement. In BIND 8, the new logging configuration took effect
074ae7bf0993ced96b32e3e85553a401f3f3eca9Andreas Gustafssonimmediately after the "logging" statement was read.
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafsson2. Zone File Compatibility
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafsson2.1. Strict 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.
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafsson2.2. Periods in SOA Serial Numbers Deprecated
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas GustafssonSome versions of BIND allow SOA serial numbers with an embedded
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssonperiod, like "3.002", and convert them into integers in a rather
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssonunintuitive way. This feature is not supported by BIND 9; serial
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssonnumbers must be integers.
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafsson2.3. Handling of Unbalanced Quotes
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas GustafssonTXT records with unbalanced quotes, like 'host TXT "foo', were not
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssontreated as errors in some versions of BIND. If your zone files
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssoncontain such records, you will get potentially confusing error
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssonmessages like "unexpected end of file" because BIND 9 will interpret
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafssoneverything up to the next quote character as a literal string.
d8417b5f3406f4ace0f3bdb228b05a7b701976d6Andreas Gustafsson3. Interoperability Impact of New Protocol 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.
69b641bf31d95fd79a50dcea2cdb0fcb23fe22c6David Lawrence$Id: migration,v 1.4 2000/07/27 23:48:49 tale Exp $