今天我也需要反向 DNS 查找，我找到了非常简单的标准解决方案:

Today I also needed reverse DNS lookup and I've found very simple standard solution:

require 'resolv'
host_name = Resolv.getname(ip_address_here)

它似乎使用了超时，这有助于在粗糙的情况下.

It seems it uses timeout which helps in rough cases.