/etc/hosts 配置文件中含有 IP 地址到主机名、域名以及别名的静态映射关系，又可以将其当成是 DNS 解析服务的本地映射表，并且在系统进行 DNS 解析时，它们的优先级比 DNS Server 的更高。
别名：This is often done when previewing a site during development before the domain is live.
域名：This is useful when hosting a web or mail server.
映射 IPv6 地址：Map the alias
backupserver to the given private IPv6 address:
阻断流量：Block all traffic to and from the domain
example.com. This is frequently used for content filtering or blocking advertisements 广告 via a hosts file.
Set a fully qualified domain name (FQDN). In the example below, replace example_hostnamewith your system’s hostname. The domain example.com can be a public internet domain (ex. a public website) or the domain of a private network (ex. your home LAN), or a subdomain (subdomain.example.com). It’s important to add the FQDN entry immediately after the localhost line, so it looks like below:
127.0.0.1 localhost 127.0.1.1 hostname.example.com example_hostname
A FQDN does not necessarily need to have any relationship to websites or other services hosted on the server (although it may if you wish). As an example, you might host
www.something.com on your server, but the system’s FQDN might be
The domain you assign as your system’s FQDN should have an “A” record in DNS pointing to your Linode’s IPv4 address. For IPv6, you should set up a “AAAA” record in DNS pointing to your Linode’s IPv6 address. For more information on configuring DNS, see our DNS recordsguide.
配置 DNS 解析来源优先顺序
hosts: files dns myhostname 这一行中
To ensure than the system prefers resolving domains listed in your hosts file over DNS resolution, the word
files must appear in the line before