CODEWITHSUNDEEP
amazon-web-servicesamazon-vpc
red888
red888

Reputation: 31610

Why cant you auto-assign EIPs at the subnet level?

Its strange to me this feature is missing so I'm assuming maybe there is something fundamental I dont understand about this.

At the subnet level I can enable "Auto-assign Public IP" to automatically assign ephemeral public IPs to any new instances launched in the subnet.

But why is there not an "Auto-assign Elastic IP" here? Why can't I have an EIP automatically allocated and assigned to new instances launched in the subnet? Would auto-assigning EIPs be problematic in some way?

Or maybe this is Amazon just trying to dissuade customers from reserving a lot of their address space?

Upvotes: 1

Views: 34

Answers (1)

Sergey Kovalev
Sergey Kovalev

Reputation: 9411

IMO, such option will get a lot of customers into trouble.

  1. Should we allocate new EIP or assign an existing one if we have an unassigned EIP?
  2. Should we release EIP once the instance is terminated?
  3. What would happen if we have some autoscaling policy that creates a new instance every 10 minutes? Will a (pretty expensive) new EIP be allocated each time?

Architecturally, EIPs are not for servers/instances. They are for services. So assigning EIP to an instance right away doesn't make much sense.

Upvotes: 2

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