This chapter assumes that the reader has a basic understanding of BIND and DNS; it does not attempt to explain the concepts of BIND and DNS. This chapter does explain how to use the Domain Name Service Configuration Tool (redhat-config-bind) to configure basic BIND server zones. The Domain Name Service Configuration Tool creates the /etc/named.conf configuration file and the zone configuration files in the /var/named/ directory each time changes are applied.
Important | |
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Do not edit the /etc/named.conf configuration file. Domain Name Service Configuration Tool generates this file after changes are applied. To configure settings that are not configurable using Domain Name Service Configuration Tool, add them to the /etc/named.custom file. |
The Domain Name Service Configuration Tool requires the X Window System and root access. To start the Domain Name Service Configuration Tool, go to the Main Menu Button (on the Panel) => System Settings => Server Settings => Domain Name Service or type the command redhat-config-bind at a shell prompt (for example, in an XTerm or GNOME Terminal).
The Domain Name Service Configuration Tool configures the default zone directory to be /var/named/. All zone files specified are relative to this directory. The Domain Name Service Configuration Tool also includes basic syntax checking when values are entered. For example, if a valid entry is an IP address, only numbers and periods (.) are allowed in the text area.
The Domain Name Service Configuration Tool allows for the addition of a forward master zone, a reverse master zone, and a slave zone. After adding the zones, they can be edited or deleted from the main window as shown in Figure 28-1.
After adding, editing, or deleting a zone, click the Save button or select File => Save to write the /etc/named.conf configuration file and all the individual zone files in the /var/named/ directory. Saving changes also causes the named service to reload the configuration files. Selecting File => Quit saves the changes before quitting the application.
To add a forward master zone (also known as a primary master), click the New button, select Forward Master Zone, and enter the domain name for the master zone in the Domain name text area.
A new window as shown in Figure 28-2 appears with the following options:
Name — Domain name that was just entered in the previous window.
File Name — File name of the DNS database file, relative to /var/named. It is preset to the domain name with .zone appended to it.
Contact — Email address of the main contact for the master zone.
Primary Nameserver (SOA) — State of authority (SOA) record. This specifies the nameserver that is the best resource of information for this domain.
Serial Number — The serial number of the DNS database file. This number must be incremented each time the file is changed, so that the slave nameservers for the zone retrieve the latest data. The Domain Name Service Configuration Tool increments this number each time the configuration changes. It can also be incremented manually by clicking the Set button next to the Serial Number value.
Time Settings — The Refresh, Retry, Expire, and Minimum TTL (Time to Live) values that are stored in the DNS database file. All values are in seconds.
Records — Add, edit, and delete record resources of type Host, Alias, and Name server.
A Primary Nameserver (SOA) must be specified, and at least one nameserver record must be specified by clicking the Add button in the Records section.
After configuring the Forward Master Zone, click OK to return to the main window as shown in Figure 28-1. From the pulldown menu, click Save to write the /etc/named.conf configuration file, write all the individual zone files in the /var/named directory, and have the daemon reload the configuration files.
The configuration creates an entry similar to the following in /etc/named.conf:
zone "forward.example.com" { type master; file "forward.example.com.zone"; }; |
It also creates the file /var/named/forward.example.com.zone with the following information:
$TTL 86400 @ IN SOA ns.example.com. root.localhost ( 2 ; serial 28800 ; refresh 7200 ; retry 604800 ; expire 86400 ; ttl ) IN NS 192.168.1.1. |