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58 lines
2.3 KiB
Plaintext
58 lines
2.3 KiB
Plaintext
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Copyright (C) 2000 Internet Software Consortium.
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See COPYRIGHT in the source root or http://www.isc.org/copyright for terms.
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BIND 8 to BIND 9 Migration Notes
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BIND 9 is designed to be mostly upwards compatible with BIND 8, but
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there is still a number of caveats you should be aware of when
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upgrading an existing BIND 8 installation to use BIND 9.
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Unimplemented Options and Changed Defaults
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Some BIND 8 configuration options are still unimplemented in BIND 9,
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and the default values of some options have changed. If your
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named.conf file uses an unimplemented option, named will log a warning
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message. A message is also logged about each option whose default has
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changed unless the option is set explicitly in named.conf.
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Strict RFC1035 Interpretation of TTLs in Zone Files
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BIND 8 allowed you to omit all TTLs from a zone file, and used the
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value of the SOA MINTTL field as a default for missing TTL values.
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BIND 9 enforces strict compliance with the RFC1035 and RFC2308 TTL
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rules. The default TTL is the value specified with the $TTL
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directive, or the previous explicit TTL if there is no $TTL directive.
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If there is no $TTL directive and the first RR in the file does not
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have an explicit TTL field, the error message "no TTL specified" is
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logged and loading the zone file fails.
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To avoid problems, use a $TTL directive in each zone file.
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Interoperability Impact of New Query Features
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BIND 9 uses EDNS0 (RFC2671) to advertise its receive buffer size. It
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also sets the AD bit in queries to indicate that it wishes to receive
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DNSSEC responses (this usage of the AD bit is not yet standard, but
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hopefully it will be soon).
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Most older servers that do not support EDNS0 and/or DNSSEC, including
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all known versions of BIND, will send a FORMERR or NOTIMP response to
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these queries. When this happens, BIND 9 will automatically retry the
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query without EDNS0 and AD.
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Unfortunately, there exists at least one non-BIND name server
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implementation that silently ignores these queries instead of sending
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an error response. Resolving names in zones where all or most
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authoritative servers use this server will be very slow or fail
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completely. We have contacted the manufacturer of the name server in
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case and are trying to resolve the issue with them.
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$Id: migration,v 1.1 2000/06/30 22:44:08 gson Exp $
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