/ etc / network / interfacesのdns-searchオプションの意味は何ですか？

誰でもファイル内のdns-searchディレクティブについて説明できますか？/etc/network/interfaces

iface eth0 inet static
    address 192.168.3.3
    netmask 255.255.255.0
    gateway 192.168.3.1
    dns-search example.com
    dns-nameservers 192.168.3.45 192.168.8.10

必須ですか？そして、どうすれば設定できますか？

dns-search DNSルックアップに追加するドメインを決定します。

通常、ここで返されるドメインと同じドメインを指定しますhostname -f。

詳細については、次の引用を参照してくださいman resolv.conf。

   search Search list for host-name lookup.
          The  search  list  is  normally  determined from the local domain name; by default, it contains only the local domain
          name.  This may be changed by listing the desired domain search path following the search keyword with spaces or tabs
          separating  the  names.  Resolver queries having fewer than ndots dots (default is 1) in them will be attempted using
          each component of the search path in turn until a match is found.  For environments with multiple  subdomains  please
          read options ndots:n below to avoid man-in-the-middle attacks and unnecessary traffic for the root-dns-servers.  Note
          that this process may be slow and will generate a lot of network traffic if the servers for the  listed  domains  are
          not local, and that queries will time out if no server is available for one of the domains.

          The search list is currently limited to six domains with a total of 256 characters.