一个域名是否可能有多个相应的IP地址？

Question

例如,当我们连接时www.example.com,首先我们尝试连接192.0.2.1.如果第一次尝试失败,那么我们尝试192.0.2.222.

可能吗？我们可以为一个域名注册多个备份IP地址吗？

Answer 1

这是循环DNS.这是一个非常简单的负载平衡解决方案.通常,DNS服务器会为每个传入的DNS请求轮换/随机播放DNS记录.不幸的是,它不是故障转移的真正解决方案.如果其中一个服务器发生故障,一些访问者仍将被定向到此故障服务器.

Answer 2

你能行的.这就是大家伙所做的事情.

第一个查询:

» host google.com 
google.com has address 74.125.232.230
google.com has address 74.125.232.231
google.com has address 74.125.232.232
google.com has address 74.125.232.233
google.com has address 74.125.232.238
google.com has address 74.125.232.224
google.com has address 74.125.232.225
google.com has address 74.125.232.226
google.com has address 74.125.232.227
google.com has address 74.125.232.228
google.com has address 74.125.232.229

下一个查询:

» host google.com
google.com has address 74.125.232.224
google.com has address 74.125.232.225
google.com has address 74.125.232.226
google.com has address 74.125.232.227
google.com has address 74.125.232.228
google.com has address 74.125.232.229
google.com has address 74.125.232.230
google.com has address 74.125.232.231
google.com has address 74.125.232.232
google.com has address 74.125.232.233
google.com has address 74.125.232.238

如您所见,IP列表周围旋转,但两个IP之间的相对顺序保持不变.

更新:我看到几个评论吹嘘DNS循环法如何不便于故障转移,所以这里是摘要:DNS 不是故障转移.因此,故障转移显然不太好.它从未被设计为故障转移的解决方案.