FQDN:(Fully Qualified Domain Name) 全限定域名: 同时带有主机名和域名的名称
其实就是标注一个主机的完整域名. 比如我的域名为 ifrom.top 那么它的邮件服务器的主机名为 mail, 所以它的 FQDN 为: mail.ifrom.top
Linux 获取主机名 的命令为:
- ? ~ hostname -f
- ? ~ hostname --fqdn
- ? ~ hostname --long
三个都返回 fqdn 的值.
我们通过 man hostname 可以发现, 其中有对 fqdn 有更问详细的讲解:
- THE FQDN
- The FQDN (Fully Qualified Domain Name) of the system is the name that the resolver(3) returns for the host name, such as, ursula.example.com. It is usually the hostname followed
- by the DNS domain name (the part after the first dot). You can check the FQDN using hostname --fqdn or the domain name using dnsdomainname.
- You cannot change the FQDN with hostname or dnsdomainname.
- The recommended method of setting the FQDN is to make the hostname be an alias for the fully qualified name using /etc/hosts, DNS, or NIS. For example, if the hostname was
- "ursula", one might have a line in /etc/hosts which reads
- 127.0.1.1 ursula.example.com ursula
- Technically: The FQDN is the name getaddrinfo(3) returns for the host name returned by gethostname(2). The DNS domain name is the part after the first dot.
- Therefore it depends on the configuration of the resolver (usually in /etc/host.conf) how you can change it. Usually the hosts file is parsed before DNS or NIS, so it is most com-
- mon to change the FQDN in /etc/hosts.
- If a machine has multiple network interfaces/addresses or is used in a mobile environment, then it may either have multiple FQDNs/domain names or none at all. Therefore avoid
- using hostname --fqdn, hostname --domain and dnsdomainname. hostname --ip-address is subject to the same limitations so it should be avoided as well.
来源: http://www.bubuko.com/infodetail-2718532.html