Subdomains
Back to Networking
In DNS hierarchy a subdomain is a domain that is part of the main domain
- west.example.com and east.example.com are subdomains of example.com, which is a subdomain of
com top-level domain (TLD)
- subdomains are defined by editing the DNS zone file pertaining to the parent domain
DNS Zones
A DNS zone is a portion of the DNS namespace that is delegating control of portions of the namespace. A zone can contain multiple domains. A server can contain multiple zones. It is important for resolving the ip address of subdomains.
The zone itself is analogous to a database of subdomain resolutions, which can point to other more specific databases for more specific subdomains.
- Server A can host the zone for a domain kevintpeng.me, and could for example resolve all subdomains except for testing.kevintpeng.me which can be delegated as a separate DNS zone on a new server, Server B
- Server A holds no fine details about the subdomains within testing.kevintpeng.me.
