09 Running Multiple Domains
Overview
The Domain Name System (DNS) is a distributed hierarchical database used to translate domain names into IP addresses. Production DNS infrastructure requires redundancy, replication, and careful operational monitoring.
BIND9 remains one of the most widely deployed authoritative DNS servers. Administrators use it to host zones, replicate them to secondary servers, and implement security features such as DNSSEC.
This section explains engineering considerations involved in deploying DNS infrastructure reliably.
Concepts
The Domain Name System (DNS) is a distributed hierarchical database used to translate domain names into IP addresses. Production DNS infrastructure requires redundancy, replication, and careful operational monitoring.
BIND9 remains one of the most widely deployed authoritative DNS servers. Administrators use it to host zones, replicate them to secondary servers, and implement security features such as DNSSEC.
This section explains engineering considerations involved in deploying DNS infrastructure reliably.
Configuration
The Domain Name System (DNS) is a distributed hierarchical database used to translate domain names into IP addresses. Production DNS infrastructure requires redundancy, replication, and careful operational monitoring.
BIND9 remains one of the most widely deployed authoritative DNS servers. Administrators use it to host zones, replicate them to secondary servers, and implement security features such as DNSSEC.
This section explains engineering considerations involved in deploying DNS infrastructure reliably.
Operational Considerations
The Domain Name System (DNS) is a distributed hierarchical database used to translate domain names into IP addresses. Production DNS infrastructure requires redundancy, replication, and careful operational monitoring.
BIND9 remains one of the most widely deployed authoritative DNS servers. Administrators use it to host zones, replicate them to secondary servers, and implement security features such as DNSSEC.
This section explains engineering considerations involved in deploying DNS infrastructure reliably.
Design Notes
The Domain Name System (DNS) is a distributed hierarchical database used to translate domain names into IP addresses. Production DNS infrastructure requires redundancy, replication, and careful operational monitoring.
BIND9 remains one of the most widely deployed authoritative DNS servers. Administrators use it to host zones, replicate them to secondary servers, and implement security features such as DNSSEC.
This section explains engineering considerations involved in deploying DNS infrastructure reliably.
Example named.conf configuration
options {
directory "/var/cache/bind";
recursion no;
allow-query { any; };
};
zone "example.com" {
type master;
file "/etc/bind/db.example.com";
allow-transfer { 192.168.1.10; };
};
Example zone file
$TTL 86400 @ IN SOA ns1.example.com. admin.example.com. ( 2024010101 3600 1800 604800 86400 ) @ IN NS ns1.example.com. @ IN NS ns2.example.com. www IN A 192.168.1.20 mail IN A 10.0.0.25