Will my running EC2 instance drop its current public IP if I associate an Elastic IP to it?

Question

I am running an EC2 instance with a public IP. This IP is not elastic, so if I were to restart the instance, I would lose it.

When I created the instance, I did not know about this, so I configured my domain name to point to that IP as if it were set in stone.

Now I realized that I risk that my app be unreachable if the IP changes after a restart.

What would the correct procedure to assign an Elastic IP to this instance without downtime?

score 1 · Accepted Answer · answered Nov 22 '18 at 11:43

1

There will be not that much of downtime. it will be a couple of secs. just get the new ElasticIP and point the DNS to new. Or if you want to do without Downtime, Then plan to add Loadbalancer with your instance and point the domain to Loadbalancer. there will be no downtime

answered Nov 22 '18 at 11:43

AnmolNagpal

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Won't there be downtime while the DNS change propagates? – Salvatore Iovene Nov 23 '18 at 12:12
No, Becuase your old DNS and NEW DNS are pointing to the same server. Only Diff will be earlier it was on EC2 now it will be LB. Rest will be the same. – AnmolNagpal Nov 23 '18 at 13:58
Thanks, my question was related to just changing the DNS without a LB. But I understand now how I could do it with no downtime using a LB. Thanks! – Salvatore Iovene Nov 23 '18 at 20:57

score 0 · Answer 2 · answered Nov 22 '18 at 11:20

0

The public IP which is auto assigned to your instance will change once you restart/stop n start your instance. Creation and assigning of the Elastic IP wont cause any issue but the domain name configuration will have to be changed. the domain name configuration was done through AWS or any other service providers?

answered Nov 22 '18 at 11:20

kavya sudeep

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It's done via Cloudflare. I can set a very short TTL (I think the shortest is 1 or 2 minutes) and that should limit the downtime to 2 minutes, I think. – Salvatore Iovene Nov 23 '18 at 12:13

Will my running EC2 instance drop its current public IP if I associate an Elastic IP to it?

2 Answers2