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to make a subdomain, you just have to set a DNS record!
To set up cats.yourdomain.com, create a DNS record like this in your authoritative nameservers:
cats.yourdomain.com A 1.2.3.4
yourdomain is the name
A is the record type
1.2.3.4 is the value
there are 2 ways a nameserver can handle subdomains
- Store their DNS records itself
nameserver, represented by a box with a smiley face wearing a crown: here’s the IP for cats.yourdomain.com!
- Redirect to another authoritative nameserver
(this happens if you set an NS record for the subdomain, it’s called “delegation”)
nameserver: ask this other DNS server instead!
you can create multiple levels of subdomains
For example, you can make:
a.b.c.d.e.f.g.example.com
up to 127 levels is allowed!
www is a common subdomain
Usually www.yourdomain.com and yourdomain.com point to the exact same IP address.
If you wanted to confuse people, you could make them totally different websites!
panel 5
Illustration of a smiling stick figure with curly hair.
person: I love using subdomains for my projects (like dns-lookup.jvns.ca) because they’re free, I can give a subdomain a different IP, and it keeps projects separate.