Setting DNS in RedHat Enterprise4

To solve problem about DNS, needs to perform the following tasks:
1. Configure a Linux node as a master DNS server for authenticated hosts.
2. Configure the forward zone file.
3. Configure the reverse zone file.
4. Configure the DNS.
5. Start named daemon for the master DNS server.

1. Configure a Linux node as a master DNS server for authenticated hosts.
To configure a Linux node as a master DNS server for RZTV, edit the /etc/named.conf file as follows:
zone "rztv.com" IN {
type master;
file "rztv.zone";
allow-update { none; };
};

zone "3.168.192.in-addr.arpa" IN {
type master;
file "named.rztv";
allow-update { none; };
};

Note:
A zone statement defines the characteristics of a zone and holds all the information regarding a zone, including the location of its configurations file. The following are some of the zone-options directives:
a. allow-update: Specifies the hosts that are allowed to dynamically update information in their zone.
b. file: Specifies the name of the zone’s configuration data file.
c. type: Specifies the types of zones, which are:
- master: Designates a name server as authoritative for the zone.
- forward: Forwards all requests regarding the information about the current zone to other name servers.
- hint: Points to the root name servers.

2. Configure the forward zone file.
Edit the /var/named/chroot/var/named/rztv.zone file in the linux node, which will act as the master DNS server, as follows:
$TTL 86400
@ IN SOA rztv.com. root.rztv.com. (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum

IN NS rztv.com.
rztv.com. IN A 192.168.3.130

Note:
1. $TTL: Used to set the default Time to Live (TTL) value for the zone. The TTL directive takes the value in seconds.
2. A: Address record, maps the host name to the IP address.
3. NS: Name Server record, defines the authoritative name servers for a particular zone.
4. SOA: State Of Authority record provides authoritative information about a domain. Contains the authoritative information about a namespace to the name server.
3. Configure the reverse zone file.
Edit the /var/named/chroot/var/named/named.rztv file in the Linux node, which will act as the master DNS server, as follows:
$TTL 86400
@ IN SOA rztv.com. root.rztv.com. (
1997022700 ; Serial
28800 ; Refresh
14400 ; Retry
3600000 ; Expire
86400 ) ; Minimum
IN NS rztv.com.

130 IN PTR rztv.com.
Note:
- PTR: PoinTeR record, maps an IP address to the host name. PTR are primarily used for reverse name solution, as they point IP addresses back to a particular host name.

4. Configure the DNS.
; generated by /sbin/dhclient-script
search localdomain
nameserver 192.168.3.130