mirror of
https://github.com/isc-projects/bind9.git
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53a5776025
Use the new role :iscman: to replace all occurences or ``binary``
with :iscman:`binary`, creating a hyperlink to the manual page.
Generated using:
find bin -name *.rst | xargs fgrep --files-with-matches '.. iscman' | xargs -I{} -n1 basename {} .rst > /tmp/progs
for PROG in $(cat /tmp/progs); do find -name '*.rst' | xargs sed -i -e "s/\`\`$PROG\`\`/:iscman:\`$PROG\`/g"; done
Additional hand-edits were done mainly around filter-aaaa and
filter-a which are program names and and option names at the
same time. Couple more edits was neede to fix .rst syntax broken by
automatic replacement.
86 lines
2.8 KiB
ReStructuredText
86 lines
2.8 KiB
ReStructuredText
.. Copyright (C) Internet Systems Consortium, Inc. ("ISC")
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..
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.. SPDX-License-Identifier: MPL-2.0
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..
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.. This Source Code Form is subject to the terms of the Mozilla Public
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.. License, v. 2.0. If a copy of the MPL was not distributed with this
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.. file, you can obtain one at https://mozilla.org/MPL/2.0/.
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..
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.. See the COPYRIGHT file distributed with this work for additional
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.. information regarding copyright ownership.
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.. highlight: console
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.. iscman:: filter-a
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.. _man_filter-a:
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filter-a.so - filter A in DNS responses when AAAA is present
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---------------------------------------------------------------
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Synopsis
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~~~~~~~~
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:program:`plugin query` "filter-a.so" [{ parameters }];
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Description
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~~~~~~~~~~~
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:program:`filter-a.so` is a query plugin module for :iscman:`named`, enabling
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:iscman:`named` to omit some IPv4 addresses when responding to clients.
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For example:
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::
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plugin query "filter-a.so" {
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filter-a-on-v6 yes;
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filter-a-on-v4 yes;
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filter-a { 192.0.2.1; 2001:db8:2::1; };
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};
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This module is intended to aid transition from IPv4 to IPv6 by
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withholding IPv4 addresses from DNS clients which are not connected to
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the IPv4 Internet, when the name being looked up has an IPv6 address
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available. Use of this module is not recommended unless absolutely
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necessary.
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Note: This mechanism can erroneously cause other servers not to give
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A records to their clients. If a recursing server with both IPv6 and
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IPv4 network connections queries an authoritative server using this
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mechanism via IPv6, it is denied A records even if its client is
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using IPv4.
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Options
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~~~~~~~
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``filter-a``
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This option specifies a list of client addresses for which A filtering is to
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be applied. The default is ``any``.
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``filter-a-on-v6``
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If set to ``yes``, this option indicates that the DNS client is at an IPv6 address, in
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``filter-a``. If the response does not include DNSSEC
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signatures, then all A records are deleted from the response. This
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filtering applies to all responses, not only authoritative
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ones.
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If set to ``break-dnssec``, then A records are deleted even when
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DNSSEC is enabled. As suggested by the name, this causes the response
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to fail to verify, because the DNSSEC protocol is designed to detect
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deletions.
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This mechanism can erroneously cause other servers not to give A
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records to their clients. If a recursing server with both IPv6 and IPv4
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network connections queries an authoritative server using this
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mechanism via IPv6, it is denied A records even if its client is
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using IPv4.
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``filter-a-on-v4``
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This option is identical to ``filter-a-on-v6``, except that it filters A responses
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to queries from IPv4 clients instead of IPv6 clients. To filter all
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responses, set both options to ``yes``.
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See Also
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~~~~~~~~
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BIND 9 Administrator Reference Manual.
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