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: /var/named/ zone file syntax resource record formats named-checkzone named-compilezone dig nslookup host 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 <ttl value> <domain name>. IN SOA <nameserver name>. <user.email>. ( <serial>; serial number <refresh>; refresh value <retry>; retry value <expire>; expire value <n-ttl>; negative caching TTL of 1 day <domain name>. IN NS <authoritative NS name>. <domain name>. IN NS <authoritative NS name>. ... <hostname>. IN A <IP address> <hostname>. IN A <IP address> ... Create and maintain DNS zones For reverse mappings : $TTL <ttl value> <reverse net addr>.in-addr.arpa. IN SOA <NS name>. <user.email>. ( <serial>; serial number <refresh>; refresh value <retry>; retry value <expire>; expire value <n-ttl>; negative caching TTL of 1 day <rev net addr>.in-addr.arpa. IN NS <authoritative NS name>. <rev net addr>.in-addr.arpa. IN NS <authoritative NS name>. ... <rev IP addr>.in-addr.arpa. IN PTR <fqdn>. <rev IP addr>.in-addr.arpa. IN PTR <fqdn>. ... Key terms, files and utilities : Content of /var/named Zone file syntax Resources record formats Dig Nslookup Host Exercises linux