LPI Linux Certification/Create & Maintain DNS Zones

Detailed Objectives
(LPIC-2 Version 4.5)

Weight: 3

Description: Candidates should be able to create a zone file for a forward or reverse zone or root level server. This objective includes setting appropriate values for records, adding hosts in zones and adding zones to the DNS. A candidate should also be able to delegate zones to another DNS server.

Key Knowledge Areas:
 * BIND 9.x configuration files, terms and utilities.
 * Utilities to request information from the DNS server.
 * Layout, content and file location of the BIND zone files.
 * Various methods to add a new host in the zone files, including reverse zones.

Terms and Utilities:
 * zone file syntax
 * resource record formats
 * named-checkzone
 * named-compilezone
 * named-compilezone

Create and maintain DNS zones
DNS zone files are composed mostly by resources records (RR) Resource records must start in the first column of a line The order in which they appear is not important, but most people tend to follow the order in the DNS RFCs SOA (Start Of Authority) : indicates authority for this zone NS (NameServer) : lists a nameserver for this zone Other records :

A : name-to-address mapping PTR : address-to-name mapping CNAME (canonical name) : aliases Don't forget to create a zone for 127.0.0 ! Create and maintain DNS zones Usual zone file format :

$TTL . IN SOA. . ( serial number ; refresh value ; retry value ;  expire value ;  negative caching TTL of 1 day .  IN  NS  . .  IN  NS  . ... .  IN  A   .  IN  A   ...

Create and maintain DNS zones For reverse mappings : $TTL .in-addr.arpa. IN SOA . . ( serial number ; refresh value ; retry value ;  expire value ;  negative caching TTL of 1 day .in-addr.arpa.  IN  NS  . .in-addr.arpa.  IN  NS  . ... .in-addr.arpa.  IN  PTR  . .in-addr.arpa.  IN  PTR  . ...

Key terms, files and utilities : Content of /var/named Zone file syntax Resources record formats Dig Nslookup Host