What is DNS?
DNS is short for Domain Name System. It converts the letter-based domain names humans use (www.ren-fei.com) into the IP addresses computers use (101.199.103.19) — that’s what DNS does, usually in a few milliseconds. Converting a domain to an IP is called domain resolution.
What do those resolution parameters mean?
Let’s use DNSpod as an example; it’s the same everywhere else.
First add your domain in DNSpod, then change the NS records at your domain registrar to: f1g1ns1.dnspod.net and f1g1ns2.dnspod.net. Don’t know how? Check DNSpod’s official help — it’s all documented there, so I won’t repeat it. Click the added domain to enter the management panel, click Add, and see what’s there:
We see these parameters: host record, record type, line, record value, TTL.
What does host record mean? If you want to resolve bbs.ren-fei.com, the host record is bbs; for www.ren-fei.com it’s www; for ren-fei.com it’s @ — @ means empty.
Record types include: A, CNAME, MX, TXT, NS, AAAA, explicit URL, SRV.
An A record is a plain IP address; the record value is the IP — the most commonly used; here you fill in the IP your host gave you.
CNAME means pointing the domain to another domain’s A record; the record value is a domain name — here you fill in the free subdomain your host gave you (choose either A or CNAME).
An MX record is the mail exchange record, used with email — for example, if you use Tencent’s domain email, enterprise email, or your own mail server, you need to set an MX record; the host is usually @ (empty).
A TXT record is generally for anti-spam; here you can declare your mail server’s IP address, and the other party’s mail server checks it first — if the IP doesn’t match, it can refuse the message, and it also prevents someone from impersonating you.
An NS record is the domain’s name server address. When you want a subdomain resolved by another resolver, you set an NS record; normally not needed.
An AAAA record is essentially an A record, except A records IPv4 addresses and AAAA records IPv6 addresses; if your host provides an IPv6 address, you need to set an AAAA record.
An explicit URL is a web redirect — when this domain is visited, it jumps to another domain. DNSpod only offers explicit (301) redirects, and limits the number of records, apparently to 10.
An SRV record is a type of resource record supported in the DNS server database; it records which computer provides which service. I’ve never used it, so I won’t say more.