Red Hat ENTERPRISE LINUX 3 Reference Manual

Also see for ENTERPRISE LINUX 3 - SECURITY GUIDE: Tuning guide Installation guide Installation guide Installation guide Manual

Contents

Chapter 12. Berkeley Internet Name Domain (BIND) 19712.5.4. IP version 6BIND version 9 supports name service in IP version 6 (IPv6) environments through the use of A6 zonerecords.If the network environment includes both IPv4 and IPv6 hosts, use the lwresd lightweight resolverdaemon on all network clients. This daemon is a very efficient, caching-only nameserver which un-derstands the new A6 and DNAME records used under IPv6. See the lwresd man page for more infor-mation.12.6. Common Mistakes to AvoidIt is very common for beginners to make mistakes when editing BIND configuration files. Be sure toavoid the following issues:• Take care to increment the serial number when editing a zone file.If the serial number is not incremented, the master nameserver will have the correct, new informa-tion, but the slave nameservers will never be notified of the change or attempt to refresh their dataof that zone.• Be careful to use ellipses and semi-colons correctly in the /etc/named.conf file.An omitted semi-colon or unclosed ellipse section can cause named to refuse to start.• Remember to place periods (.) in zone files after all FQDNs and omit them on hostnames.A period at the end of a domain name denotes a fully qualified domain name. If the period isomitted, then named appends the name of the zone or the $ORIGIN value to complete it.• If a firewall is blocking connections from the named program to other nameservers, edit its config-uration file.By default, BIND version 9 uses random ports above 1024 to query other nameservers. Somefirewalls, however, expect all nameservers to communicate using only port 53. Force named to useport 53 by adding the following line to the options statement of /etc/named.conf:query-source address * port 53;12.7. Additional ResourcesThe following sources of information will provide additional resources regarding BIND.12.7.1. Installed Documentation• BIND features a full-range of installed documentation covering many different topics, each placedin its own subject directory:• /usr/share/doc/bind-6 version-number7 / Directory — A list of the most recent fea-tures. Replace 8 version-number9 with the version of bind installed on the system.• /usr/share/doc/bind-6 version-number7 /arm/ Directory — Contains HTML andSGML of the BIND 9 Administrator Reference Manual, which details BIND resourcerequirements, how to configure different types of nameservers, perform load balancing, andother advanced topics. For most new users of BIND, this is the best place to start. Replace8version-number9 with the version of bind installed on the system.