DO (Digital Ocean) 新出的 Floating IP 功能是干什么用的，没太看明白！

[bestsanmao]

今天收到 DO 的推广邮件，说是出新功能了，新功能叫 Floating IP ，点进去看了半天没看明白到底干什么用的
谁清楚？麻烦讲解一下！

[jasontse]

IP 层面的 HA ，主机挂了 IP 切到备机上，有点类似 VRRP 。

[Moker]

@jasontse 那这个似乎是能用它的当作备机？感觉还是 DNS 切好啊

[tobyxdd]

A floating IP address is used to support failover in a high-availability cluster. The cluster is configured such that only the active member of the cluster "owns" or responds to that IP address at any given time. Should the active member fail, then "ownership" of the floating IP address would be transferred to a standby member to promote it as the new active member. Specifically, the member to be promoted issues a gratuitous ARP, announcing the new MAC address – to – IP address association.

[tobyxdd]

dns 切毕竟生效慢

[jasontse]

@Moker DNS 有 TTL Cache 切换不及时，这个是备机直接接管 IP 。

[nyacat]

貌似有点想 Linode 的 ip clone?