874 lines
32 KiB
Plaintext
874 lines
32 KiB
Plaintext
Frequently Asked Questions about BIND 9
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Copyright © 2004-2008 Internet Systems Consortium, Inc. ("ISC")
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Copyright © 2000-2003 Internet Software Consortium.
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-----------------------------------------------------------------------
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1. Compilation and Installation Questions
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Q: I'm trying to compile BIND 9, and "make" is failing due to files not
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being found. Why?
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A: Using a parallel or distributed "make" to build BIND 9 is not
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supported, and doesn't work. If you are using one of these, use normal
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make or gmake instead.
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Q: Isn't "make install" supposed to generate a default named.conf?
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A: Short Answer: No.
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Long Answer: There really isn't a default configuration which fits any
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site perfectly. There are lots of decisions that need to be made and
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there is no consensus on what the defaults should be. For example
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FreeBSD uses /etc/namedb as the location where the configuration files
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for named are stored. Others use /var/named.
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What addresses to listen on? For a laptop on the move a lot you may
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only want to listen on the loop back interfaces.
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Who do you offer recursive service to? Is there are firewall to
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consider? If so is it stateless or stateful. Are you directly on the
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Internet? Are you on a private network? Are you on a NAT'd network? The
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answers to all these questions change how you configure even a caching
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name server.
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2. Configuration and Setup Questions
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Q: Why does named log the warning message "no TTL specified - using SOA
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MINTTL instead"?
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A: Your zone file is illegal according to RFC1035. It must either have a
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line like:
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$TTL 86400
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at the beginning, or the first record in it must have a TTL field, like
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the "84600" in this example:
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example.com. 86400 IN SOA ns hostmaster ( 1 3600 1800 1814400 3600 )
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Q: Why do I get errors like "dns_zone_load: zone foo/IN: loading master
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file bar: ran out of space"?
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A: This is often caused by TXT records with missing close quotes. Check
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that all TXT records containing quoted strings have both open and close
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quotes.
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Q: How do I restrict people from looking up the server version?
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A: Put a "version" option containing something other than the real version
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in the "options" section of named.conf. Note doing this will not
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prevent attacks and may impede people trying to diagnose problems with
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your server. Also it is possible to "fingerprint" nameservers to
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determine their version.
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Q: How do I restrict only remote users from looking up the server version?
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A: The following view statement will intercept lookups as the internal
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view that holds the version information will be matched last. The
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caveats of the previous answer still apply, of course.
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view "chaos" chaos {
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match-clients { <those to be refused>; };
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allow-query { none; };
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zone "." {
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type hint;
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file "/dev/null"; // or any empty file
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};
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};
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Q: What do "no source of entropy found" or "could not open entropy source
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foo" mean?
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A: The server requires a source of entropy to perform certain operations,
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mostly DNSSEC related. These messages indicate that you have no source
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of entropy. On systems with /dev/random or an equivalent, it is used by
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default. A source of entropy can also be defined using the
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random-device option in named.conf.
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Q: I'm trying to use TSIG to authenticate dynamic updates or zone
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transfers. I'm sure I have the keys set up correctly, but the server is
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rejecting the TSIG. Why?
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A: This may be a clock skew problem. Check that the the clocks on the
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client and server are properly synchronised (e.g., using ntp).
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Q: I see a log message like the following. Why?
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couldn't open pid file '/var/run/named.pid': Permission denied
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A: You are most likely running named as a non-root user, and that user
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does not have permission to write in /var/run. The common ways of
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fixing this are to create a /var/run/named directory owned by the named
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user and set pid-file to "/var/run/named/named.pid", or set pid-file to
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"named.pid", which will put the file in the directory specified by the
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directory option (which, in this case, must be writable by the named
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user).
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Q: I can query the nameserver from the nameserver but not from other
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machines. Why?
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A: This is usually the result of the firewall configuration stopping the
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queries and / or the replies.
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Q: How can I make a server a slave for both an internal and an external
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view at the same time? When I tried, both views on the slave were
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transferred from the same view on the master.
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A: You will need to give the master and slave multiple IP addresses and
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use those to make sure you reach the correct view on the other machine.
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Master: 10.0.1.1 (internal), 10.0.1.2 (external, IP alias)
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internal:
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match-clients { !10.0.1.2; !10.0.1.4; 10.0.1/24; };
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notify-source 10.0.1.1;
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transfer-source 10.0.1.1;
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query-source address 10.0.1.1;
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external:
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match-clients { any; };
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recursion no; // don't offer recursion to the world
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notify-source 10.0.1.2;
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transfer-source 10.0.1.2;
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query-source address 10.0.1.2;
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Slave: 10.0.1.3 (internal), 10.0.1.4 (external, IP alias)
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internal:
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match-clients { !10.0.1.2; !10.0.1.4; 10.0.1/24; };
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notify-source 10.0.1.3;
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transfer-source 10.0.1.3;
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query-source address 10.0.1.3;
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external:
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match-clients { any; };
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recursion no; // don't offer recursion to the world
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notify-source 10.0.1.4;
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transfer-source 10.0.1.4;
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query-source address 10.0.1.4;
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You put the external address on the alias so that all the other dns
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clients on these boxes see the internal view by default.
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A: BIND 9.3 and later: Use TSIG to select the appropriate view.
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Master 10.0.1.1:
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key "external" {
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algorithm hmac-md5;
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secret "xxxxxxxx";
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};
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view "internal" {
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match-clients { !key external; 10.0.1/24; };
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...
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};
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view "external" {
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match-clients { key external; any; };
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server 10.0.1.2 { keys external; };
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recursion no;
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...
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};
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Slave 10.0.1.2:
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key "external" {
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algorithm hmac-md5;
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secret "xxxxxxxx";
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};
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view "internal" {
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match-clients { !key external; 10.0.1/24; };
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...
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};
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view "external" {
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match-clients { key external; any; };
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server 10.0.1.1 { keys external; };
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recursion no;
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...
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};
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Q: I get error messages like "multiple RRs of singleton type" and "CNAME
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and other data" when transferring a zone. What does this mean?
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A: These indicate a malformed master zone. You can identify the exact
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records involved by transferring the zone using dig then running
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named-checkzone on it.
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dig axfr example.com @master-server > tmp
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named-checkzone example.com tmp
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A CNAME record cannot exist with the same name as another record except
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for the DNSSEC records which prove its existence (NSEC).
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RFC 1034, Section 3.6.2: "If a CNAME RR is present at a node, no other
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data should be present; this ensures that the data for a canonical name
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and its aliases cannot be different. This rule also insures that a
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cached CNAME can be used without checking with an authoritative server
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for other RR types."
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Q: I get error messages like "named.conf:99: unexpected end of input"
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where 99 is the last line of named.conf.
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A: There are unbalanced quotes in named.conf.
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A: Some text editors (notepad and wordpad) fail to put a line title
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indication (e.g. CR/LF) on the last line of a text file. This can be
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fixed by "adding" a blank line to the end of the file. Named expects to
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see EOF immediately after EOL and treats text files where this is not
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met as truncated.
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Q: How do I share a dynamic zone between multiple views?
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A: You choose one view to be master and the second a slave and transfer
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the zone between views.
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Master 10.0.1.1:
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key "external" {
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algorithm hmac-md5;
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secret "xxxxxxxx";
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};
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key "mykey" {
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algorithm hmac-md5;
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secret "yyyyyyyy";
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};
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view "internal" {
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match-clients { !key external; 10.0.1/24; };
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server 10.0.1.1 {
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/* Deliver notify messages to external view. */
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keys { external; };
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};
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zone "example.com" {
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type master;
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file "internal/example.db";
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allow-update { key mykey; };
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notify-also { 10.0.1.1; };
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};
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};
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view "external" {
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match-clients { key external; any; };
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zone "example.com" {
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type slave;
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file "external/example.db";
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masters { 10.0.1.1; };
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transfer-source { 10.0.1.1; };
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// allow-update-forwarding { any; };
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// allow-notify { ... };
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};
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};
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Q: I get a error message like "zone wireless.ietf56.ietf.org/IN: loading
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master file primaries/wireless.ietf56.ietf.org: no owner".
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A: This error is produced when a line in the master file contains leading
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white space (tab/space) but the is no current record owner name to
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inherit the name from. Usually this is the result of putting white
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space before a comment, forgetting the "@" for the SOA record, or
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indenting the master file.
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Q: Why are my logs in GMT (UTC).
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A: You are running chrooted (-t) and have not supplied local timezone
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information in the chroot area.
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FreeBSD: /etc/localtime
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Solaris: /etc/TIMEZONE and /usr/share/lib/zoneinfo
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OSF: /etc/zoneinfo/localtime
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See also tzset(3) and zic(8).
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Q: I get "rndc: connect failed: connection refused" when I try to run
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rndc.
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A: This is usually a configuration error.
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First ensure that named is running and no errors are being reported at
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startup (/var/log/messages or equivalent). Running "named -g <usual
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arguments>" from a title can help at this point.
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Secondly ensure that named is configured to use rndc either by
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"rndc-confgen -a", rndc-confgen or manually. The Administrators
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Reference manual has details on how to do this.
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Old versions of rndc-confgen used localhost rather than 127.0.0.1 in /
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etc/rndc.conf for the default server. Update /etc/rndc.conf if
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necessary so that the default server listed in /etc/rndc.conf matches
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the addresses used in named.conf. "localhost" has two address
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(127.0.0.1 and ::1).
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If you use "rndc-confgen -a" and named is running with -t or -u ensure
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that /etc/rndc.conf has the correct ownership and that a copy is in the
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chroot area. You can do this by re-running "rndc-confgen -a" with
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appropriate -t and -u arguments.
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Q: I get "transfer of 'example.net/IN' from 192.168.4.12#53: failed while
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receiving responses: permission denied" error messages.
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A: These indicate a filesystem permission error preventing named creating
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/ renaming the temporary file. These will usually also have other
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associated error messages like
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"dumping master file: sl/tmp-XXXX5il3sQ: open: permission denied"
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Named needs write permission on the directory containing the file.
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Named writes the new cache file to a temporary file then renames it to
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the name specified in named.conf to ensure that the contents are always
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complete. This is to prevent named loading a partial zone in the event
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of power failure or similar interrupting the write of the master file.
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Note file names are relative to the directory specified in options and
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any chroot directory ([<chroot dir>/][<options dir>]).
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If named is invoked as "named -t /chroot/DNS" with the following
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named.conf then "/chroot/DNS/var/named/sl" needs to be writable by the
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user named is running as.
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options {
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directory "/var/named";
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};
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zone "example.net" {
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type slave;
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file "sl/example.net";
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masters { 192.168.4.12; };
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};
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Q: I want to forward all DNS queries from my caching nameserver to another
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server. But there are some domains which have to be served locally, via
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rbldnsd.
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How do I achieve this ?
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A: options {
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forward only;
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forwarders { <ip.of.primary.nameserver>; };
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};
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zone "sbl-xbl.spamhaus.org" {
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type forward; forward only;
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forwarders { <ip.of.rbldns.server> port 530; };
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};
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zone "list.dsbl.org" {
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type forward; forward only;
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forwarders { <ip.of.rbldns.server> port 530; };
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};
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Q: Can you help me understand how BIND 9 uses memory to store DNS zones?
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Some times it seems to take several times the amount of memory it needs
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to store the zone.
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A: When reloading a zone named my have multiple copies of the zone in
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memory at one time. The zone it is serving and the one it is loading.
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If reloads are ultra fast it can have more still.
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e.g. Ones that are transferring out, the one that it is serving and the
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one that is loading.
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BIND 8 destroyed the zone before loading and also killed off outgoing
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transfers of the zone.
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The new strategy allows slaves to get copies of the new zone regardless
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of how often the master is loaded compared to the transfer time. The
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slave might skip some intermediate versions but the transfers will
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complete and it will keep reasonably in sync with the master.
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The new strategy also allows the master to recover from syntax and
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other errors in the master file as it still has an in-core copy of the
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old contents.
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Q: I want to use IPv6 locally but I don't have a external IPv6 connection.
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External lookups are slow.
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A: You can use server clauses to stop named making external lookups over
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IPv6.
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server fd81:ec6c:bd62::/48 { bogus no; }; // site ULA prefix
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server ::/0 { bogus yes; };
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3. Operations Questions
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Q: How to change the nameservers for a zone?
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A: Step 1: Ensure all nameservers, new and old, are serving the same zone
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content.
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Step 2: Work out the maximum TTL of the NS RRset in the parent and
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child zones. This is the time it will take caches to be clear of a
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particular version of the NS RRset. If you are just removing
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nameservers you can skip to Step 6.
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Step 3: Add new nameservers to the NS RRset for the zone and wait until
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all the servers for the zone are answering with this new NS RRset.
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Step 4: Inform the parent zone of the new NS RRset then wait for all
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the parent servers to be answering with the new NS RRset.
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Step 5: Wait for cache to be clear of the old NS RRset. See Step 2 for
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how long. If you are just adding nameservers you are done.
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Step 6: Remove any old nameservers from the zones NS RRset and wait for
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all the servers for the zone to be serving the new NS RRset.
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Step 7: Inform the parent zone of the new NS RRset then wait for all
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the parent servers to be answering with the new NS RRset.
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Step 8: Wait for cache to be clear of the old NS RRset. See Step 2 for
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how long.
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Step 9: Turn off the old nameservers or remove the zone entry from the
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configuration of the old nameservers.
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Step 10: Increment the serial number and wait for the change to be
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visible in all nameservers for the zone. This ensures that zone
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transfers are still working after the old servers are decommissioned.
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Note: the above procedure is designed to be transparent to dns clients.
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Decommissioning the old servers too early will result in some clients
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not being able to look up answers in the zone.
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Note: while it is possible to run the addition and removal stages
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together it is not recommended.
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4. General Questions
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Q: I keep getting log messages like the following. Why?
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Dec 4 23:47:59 client 10.0.0.1#1355: updating zone 'example.com/IN':
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update failed: 'RRset exists (value dependent)' prerequisite not
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satisfied (NXRRSET)
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A: DNS updates allow the update request to test to see if certain
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conditions are met prior to proceeding with the update. The message
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above is saying that conditions were not met and the update is not
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proceeding. See doc/rfc/rfc2136.txt for more details on prerequisites.
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Q: I keep getting log messages like the following. Why?
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Jun 21 12:00:00.000 client 10.0.0.1#1234: update denied
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A: Someone is trying to update your DNS data using the RFC2136 Dynamic
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Update protocol. Windows 2000 machines have a habit of sending dynamic
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update requests to DNS servers without being specifically configured to
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do so. If the update requests are coming from a Windows 2000 machine,
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see <http://support.microsoft.com/support/kb/articles/q246/8/04.asp>
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for information about how to turn them off.
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Q: When I do a "dig . ns", many of the A records for the root servers are
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missing. Why?
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A: This is normal and harmless. It is a somewhat confusing side effect of
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the way BIND 9 does RFC2181 trust ranking and of the efforts BIND 9
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makes to avoid promoting glue into answers.
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When BIND 9 first starts up and primes its cache, it receives the root
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server addresses as additional data in an authoritative response from a
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root server, and these records are eligible for inclusion as additional
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data in responses. Subsequently it receives a subset of the root server
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addresses as additional data in a non-authoritative (referral) response
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from a root server. This causes the addresses to now be considered
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non-authoritative (glue) data, which is not eligible for inclusion in
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responses.
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The server does have a complete set of root server addresses cached at
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all times, it just may not include all of them as additional data,
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depending on whether they were last received as answers or as glue. You
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can always look up the addresses with explicit queries like "dig
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a.root-servers.net A".
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Q: Why don't my zones reload when I do an "rndc reload" or SIGHUP?
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A: A zone can be updated either by editing zone files and reloading the
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server or by dynamic update, but not both. If you have enabled dynamic
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update for a zone using the "allow-update" option, you are not supposed
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to edit the zone file by hand, and the server will not attempt to
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reload it.
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Q: Why is named listening on UDP port other than 53?
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A: Named uses a system selected port to make queries of other nameservers.
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This behaviour can be overridden by using query-source to lock down the
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port and/or address. See also notify-source and transfer-source.
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Q: I get warning messages like "zone example.com/IN: refresh: failure
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trying master 1.2.3.4#53: timed out".
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A: Check that you can make UDP queries from the slave to the master
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dig +norec example.com soa @1.2.3.4
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You could be generating queries faster than the slave can cope with.
|
|
Lower the serial query rate.
|
|
|
|
serial-query-rate 5; // default 20
|
|
|
|
Q: I don't get RRSIG's returned when I use "dig +dnssec".
|
|
|
|
A: You need to ensure DNSSEC is enabled (dnssec-enable yes;).
|
|
|
|
Q: Can a NS record refer to a CNAME.
|
|
|
|
A: No. The rules for glue (copies of the *address* records in the parent
|
|
zones) and additional section processing do not allow it to work.
|
|
|
|
You would have to add both the CNAME and address records (A/AAAA) as
|
|
glue to the parent zone and have CNAMEs be followed when doing
|
|
additional section processing to make it work. No nameserver
|
|
implementation supports either of these requirements.
|
|
|
|
Q: What does "RFC 1918 response from Internet for 0.0.0.10.IN-ADDR.ARPA"
|
|
mean?
|
|
|
|
A: If the IN-ADDR.ARPA name covered refers to a internal address space you
|
|
are using then you have failed to follow RFC 1918 usage rules and are
|
|
leaking queries to the Internet. You should establish your own zones
|
|
for these addresses to prevent you querying the Internet's name servers
|
|
for these addresses. Please see <http://as112.net/> for details of the
|
|
problems you are causing and the counter measures that have had to be
|
|
deployed.
|
|
|
|
If you are not using these private addresses then a client has queried
|
|
for them. You can just ignore the messages, get the offending client to
|
|
stop sending you these messages as they are most probably leaking them
|
|
or setup your own zones empty zones to serve answers to these queries.
|
|
|
|
zone "10.IN-ADDR.ARPA" {
|
|
type master;
|
|
file "empty";
|
|
};
|
|
|
|
zone "16.172.IN-ADDR.ARPA" {
|
|
type master;
|
|
file "empty";
|
|
};
|
|
|
|
...
|
|
|
|
zone "31.172.IN-ADDR.ARPA" {
|
|
type master;
|
|
file "empty";
|
|
};
|
|
|
|
zone "168.192.IN-ADDR.ARPA" {
|
|
type master;
|
|
file "empty";
|
|
};
|
|
|
|
empty:
|
|
@ 10800 IN SOA <name-of-server>. <contact-email>. (
|
|
1 3600 1200 604800 10800 )
|
|
@ 10800 IN NS <name-of-server>.
|
|
|
|
Note
|
|
|
|
Future versions of named are likely to do this automatically.
|
|
|
|
Q: Will named be affected by the 2007 changes to daylight savings rules in
|
|
the US.
|
|
|
|
A: No, so long as the machines internal clock (as reported by "date -u")
|
|
remains at UTC. The only visible change if you fail to upgrade your OS,
|
|
if you are in a affected area, will be that log messages will be a hour
|
|
out during the period where the old rules do not match the new rules.
|
|
|
|
For most OS's this change just means that you need to update the
|
|
conversion rules from UTC to local time. Normally this involves
|
|
updating a file in /etc (which sets the default timezone for the
|
|
machine) and possibly a directory which has all the conversion rules
|
|
for the world (e.g. /usr/share/zoneinfo). When updating the OS do not
|
|
forget to update any chroot areas as well. See your OS's documentation
|
|
for more details.
|
|
|
|
The local timezone conversion rules can also be done on a individual
|
|
basis by setting the TZ environment variable appropriately. See your
|
|
OS's documentation for more details.
|
|
|
|
Q: Is there a bugzilla (or other tool) database that mere mortals can have
|
|
(read-only) access to for bind?
|
|
|
|
A: No. The BIND 9 bug database is kept closed for a number of reasons.
|
|
These include, but are not limited to, that the database contains
|
|
proprietory information from people reporting bugs. The database has in
|
|
the past and may in future contain unfixed bugs which are capable of
|
|
bringing down most of the Internet's DNS infrastructure.
|
|
|
|
The release pages for each version contain up to date lists of bugs
|
|
that have been fixed post release. That is as close as we can get to
|
|
providing a bug database.
|
|
|
|
Q: Why do queries for NSEC3 records fail to return the NSEC3 record?
|
|
|
|
A: NSEC3 records are strictly meta data and can only be returned in the
|
|
authority section. This is done so that signing the zone using NSEC3
|
|
records does not bring names into existance that do not exist in the
|
|
unsigned version of the zone.
|
|
|
|
5. Operating-System Specific Questions
|
|
|
|
5.1. HPUX
|
|
|
|
Q: I get the following error trying to configure BIND:
|
|
|
|
checking if unistd.h or sys/types.h defines fd_set... no
|
|
configure: error: need either working unistd.h or sys/select.h
|
|
|
|
A: You have attempted to configure BIND with the bundled C compiler. This
|
|
compiler does not meet the minimum compiler requirements to for
|
|
building BIND. You need to install a ANSI C compiler and / or teach
|
|
configure how to find the ANSI C compiler. The later can be done by
|
|
adjusting the PATH environment variable and / or specifying the
|
|
compiler via CC.
|
|
|
|
./configure CC=<compiler> ...
|
|
|
|
5.2. Linux
|
|
|
|
Q: Why do I get the following errors:
|
|
|
|
general: errno2result.c:109: unexpected error:
|
|
general: unable to convert errno to isc_result: 14: Bad address
|
|
client: UDP client handler shutting down due to fatal receive error: unexpected error
|
|
|
|
A: This is the result of a Linux kernel bug.
|
|
|
|
See: <http://marc.theaimsgroup.com/?l=linux-netdev&m=113081708031466&w=
|
|
2>
|
|
|
|
Q: Why does named lock up when it attempts to connect over IPSEC tunnels?
|
|
|
|
A: This is due to a kernel bug where the fact that a socket is marked
|
|
non-blocking is ignored. It is reported that setting xfrm_larval_drop
|
|
to 1 helps but this may have negative side effects. See: <https://
|
|
bugzilla.redhat.com/show_bug.cgi?id=427629> and <http://lkml.org/lkml/
|
|
2007/12/4/260>.
|
|
|
|
xfrm_larval_drop can be set to 1 by the following procedure:
|
|
|
|
echo "1" > proc/sys/net/core/xfrm_larval_drop
|
|
|
|
Q: Why do I see 5 (or more) copies of named on Linux?
|
|
|
|
A: Linux threads each show up as a process under ps. The approximate
|
|
number of threads running is n+4, where n is the number of CPUs. Note
|
|
that the amount of memory used is not cumulative; if each process is
|
|
using 10M of memory, only a total of 10M is used.
|
|
|
|
Newer versions of Linux's ps command hide the individual threads and
|
|
require -L to display them.
|
|
|
|
Q: Why does BIND 9 log "permission denied" errors accessing its
|
|
configuration files or zones on my Linux system even though it is
|
|
running as root?
|
|
|
|
A: On Linux, BIND 9 drops most of its root privileges on startup. This
|
|
including the privilege to open files owned by other users. Therefore,
|
|
if the server is running as root, the configuration files and zone
|
|
files should also be owned by root.
|
|
|
|
Q: I get the error message "named: capset failed: Operation not permitted"
|
|
when starting named.
|
|
|
|
A: The capability module, part of "Linux Security Modules/LSM", has not
|
|
been loaded into the kernel. See insmod(8), modprobe(8).
|
|
|
|
The relevant modules can be loaded by running:
|
|
|
|
modprobe commoncap
|
|
modprobe capability
|
|
|
|
Q: I'm running BIND on Red Hat Enterprise Linux or Fedora Core -
|
|
|
|
Why can't named update slave zone database files?
|
|
|
|
Why can't named create DDNS journal files or update the master zones
|
|
from journals?
|
|
|
|
Why can't named create custom log files?
|
|
|
|
A: Red Hat Security Enhanced Linux (SELinux) policy security protections :
|
|
|
|
Red Hat have adopted the National Security Agency's SELinux security
|
|
policy (see <http://www.nsa.gov/selinux>) and recommendations for BIND
|
|
security , which are more secure than running named in a chroot and
|
|
make use of the bind-chroot environment unnecessary .
|
|
|
|
By default, named is not allowed by the SELinux policy to write, create
|
|
or delete any files EXCEPT in these directories:
|
|
|
|
$ROOTDIR/var/named/slaves
|
|
$ROOTDIR/var/named/data
|
|
$ROOTDIR/var/tmp
|
|
|
|
|
|
where $ROOTDIR may be set in /etc/sysconfig/named if bind-chroot is
|
|
installed.
|
|
|
|
The SELinux policy particularly does NOT allow named to modify the
|
|
$ROOTDIR/var/named directory, the default location for master zone
|
|
database files.
|
|
|
|
SELinux policy overrules file access permissions - so even if all the
|
|
files under /var/named have ownership named:named and mode rw-rw-r--,
|
|
named will still not be able to write or create files except in the
|
|
directories above, with SELinux in Enforcing mode.
|
|
|
|
So, to allow named to update slave or DDNS zone files, it is best to
|
|
locate them in $ROOTDIR/var/named/slaves, with named.conf zone
|
|
statements such as:
|
|
|
|
zone "slave.zone." IN {
|
|
type slave;
|
|
file "slaves/slave.zone.db";
|
|
...
|
|
};
|
|
zone "ddns.zone." IN {
|
|
type master;
|
|
allow-updates {...};
|
|
file "slaves/ddns.zone.db";
|
|
};
|
|
|
|
|
|
To allow named to create its cache dump and statistics files, for
|
|
example, you could use named.conf options statements such as:
|
|
|
|
options {
|
|
...
|
|
dump-file "/var/named/data/cache_dump.db";
|
|
statistics-file "/var/named/data/named_stats.txt";
|
|
...
|
|
};
|
|
|
|
|
|
You can also tell SELinux to allow named to update any zone database
|
|
files, by setting the SELinux tunable boolean parameter
|
|
'named_write_master_zones=1', using the system-config-securitylevel
|
|
GUI, using the 'setsebool' command, or in /etc/selinux/targeted/
|
|
booleans.
|
|
|
|
You can disable SELinux protection for named entirely by setting the
|
|
'named_disable_trans=1' SELinux tunable boolean parameter.
|
|
|
|
The SELinux named policy defines these SELinux contexts for named:
|
|
|
|
named_zone_t : for zone database files - $ROOTDIR/var/named/*
|
|
named_conf_t : for named configuration files - $ROOTDIR/etc/{named,rndc}.*
|
|
named_cache_t: for files modifiable by named - $ROOTDIR/var/{tmp,named/{slaves,data}}
|
|
|
|
|
|
If you want to retain use of the SELinux policy for named, and put
|
|
named files in different locations, you can do so by changing the
|
|
context of the custom file locations .
|
|
|
|
To create a custom configuration file location, e.g. '/root/
|
|
named.conf', to use with the 'named -c' option, do:
|
|
|
|
# chcon system_u:object_r:named_conf_t /root/named.conf
|
|
|
|
|
|
To create a custom modifiable named data location, e.g. '/var/log/
|
|
named' for a log file, do:
|
|
|
|
# chcon system_u:object_r:named_cache_t /var/log/named
|
|
|
|
|
|
To create a custom zone file location, e.g. /root/zones/, do:
|
|
|
|
# chcon system_u:object_r:named_zone_t /root/zones/{.,*}
|
|
|
|
|
|
See these man-pages for more information : selinux(8), named_selinux
|
|
(8), chcon(1), setsebool(8)
|
|
|
|
Q: Listening on individual IPv6 interfaces does not work.
|
|
|
|
A: This is usually due to "/proc/net/if_inet6" not being available in the
|
|
chroot file system. Mount another instance of "proc" in the chroot file
|
|
system.
|
|
|
|
This can be be made permanent by adding a second instance to /etc/
|
|
fstab.
|
|
|
|
proc /proc proc defaults 0 0
|
|
proc /var/named/proc proc defaults 0 0
|
|
|
|
5.3. Windows
|
|
|
|
Q: Zone transfers from my BIND 9 master to my Windows 2000 slave fail.
|
|
Why?
|
|
|
|
A: This may be caused by a bug in the Windows 2000 DNS server where DNS
|
|
messages larger than 16K are not handled properly. This can be worked
|
|
around by setting the option "transfer-format one-answer;". Also check
|
|
whether your zone contains domain names with embedded spaces or other
|
|
special characters, like "John\032Doe\213s\032Computer", since such
|
|
names have been known to cause Windows 2000 slaves to incorrectly
|
|
reject the zone.
|
|
|
|
Q: I get "Error 1067" when starting named under Windows.
|
|
|
|
A: This is the service manager saying that named exited. You need to
|
|
examine the Application log in the EventViewer to find out why.
|
|
|
|
Common causes are that you failed to create "named.conf" (usually "C:\
|
|
windows\dns\etc\named.conf") or failed to specify the directory in
|
|
named.conf.
|
|
|
|
options {
|
|
Directory "C:\windows\dns\etc";
|
|
};
|
|
|
|
5.4. FreeBSD
|
|
|
|
Q: I have FreeBSD 4.x and "rndc-confgen -a" just sits there.
|
|
|
|
A: /dev/random is not configured. Use rndcontrol(8) to tell the kernel to
|
|
use certain interrupts as a source of random events. You can make this
|
|
permanent by setting rand_irqs in /etc/rc.conf.
|
|
|
|
/etc/rc.conf
|
|
rand_irqs="3 14 15"
|
|
|
|
See also <http://people.freebsd.org/~dougb/randomness.html>.
|
|
|
|
5.5. Solaris
|
|
|
|
Q: How do I integrate BIND 9 and Solaris SMF
|
|
|
|
A: Sun has a blog entry describing how to do this.
|
|
|
|
<http://blogs.sun.com/roller/page/anay/Weblog?catname=%2FSolaris>
|
|
|
|
5.6. Apple Mac OS X
|
|
|
|
Q: How do I run BIND 9 on Apple Mac OS X?
|
|
|
|
A: If you run Tiger(Mac OS 10.4) or later then this is all you need to do:
|
|
|
|
% sudo rndc-confgen > /etc/rndc.conf
|
|
|
|
Copy the key statement from /etc/rndc.conf into /etc/rndc.key, e.g.:
|
|
|
|
key "rndc-key" {
|
|
algorithm hmac-md5;
|
|
secret "uvceheVuqf17ZwIcTydddw==";
|
|
};
|
|
|
|
Then start the relevant service:
|
|
|
|
% sudo service org.isc.named start
|
|
|
|
This is persistent upon a reboot, so you will have to do it only once.
|
|
|
|
A: Alternatively you can just generate /etc/rndc.key by running:
|
|
|
|
% sudo rndc-confgen -a
|
|
|
|
Then start the relevant service:
|
|
|
|
% sudo service org.isc.named start
|
|
|
|
Named will look for /etc/rndc.key when it starts if it doesn't have a
|
|
controls section or the existing controls are missing keys sub-clauses.
|
|
This is persistent upon a reboot, so you will have to do it only once.
|
|
|