Disabling IPv6 Name Resolution in Bind 9.x

Submitted by Tom Thorp on Thursday, September 8, 2016 - 04:36
Modified on Monday, May 2, 2022 - 16:45
Bind 9.x
If you are running a Bind 9.x server, there may be times where you need to disable IPv6 name resolution through the name server. To do so, with sudo access, do the following steps.
 
1. Edit the /etc/sysconfig/named file, and insert the following:
OPTIONS="-4"
2. To filter AAAA records on your name server, the following conditions have to be met :
  • BIND 9 must be compiled with a special build-time option (./configure --enable-filter-aaaa), and
  • an options statement to enable it (for example, filter-aaaa-on-v4 yes; and/or filter-aaaa-on-v6 yes;) must be declared in named.conf.
  • the client must not be blocked in the filter-aaaa ACL (this defaults to any, so is not generally the case)
For example : to filter AAAA records on the IPv4 protocol, edit the /etc/named.conf file to include the following statement in the 'options' section:
filter-aaaa-on-v4 yes;
Optionally, if you no longer want your name server listening to IPv6, add a comment '//' at the start of the line
listen-on-v6 port 53 { ::1; };
3. Finally, restart the Bind service using the following command.
service named restart
 
If there are any error messages on startup, look at the /var/log/messages file to diagnose the issue.
 
1) Filter AAAA option in Bind 9 (ISC Knowledgebase) -
 
 

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Tom Thorp
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