Elastic IP addresses in AWS - Step-by-Step Execution

Process Flow - Elastic IP addresses

Request Elastic IP

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AWS allocates Elastic IP

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Associate Elastic IP with EC2 Instance

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Instance uses Elastic IP for communication

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Disassociate or Release Elastic IP

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Elastic IP becomes free or reassigned

This flow shows how you request, allocate, associate, and release an Elastic IP address in AWS.

Execution Sample

AWS

1. Allocate Elastic IP
2. Associate Elastic IP with EC2 instance
3. Use Elastic IP for external access
4. Disassociate Elastic IP
5. Release Elastic IP

This sequence shows the lifecycle of an Elastic IP address from allocation to release.

Process Table

Step	Action	AWS State Change	Elastic IP Status	Instance IP Status
1	Allocate Elastic IP	Elastic IP allocated and reserved	Allocated, not associated	Instance has private IP only
2	Associate Elastic IP with EC2 instance	Elastic IP linked to instance	Associated	Instance now reachable via Elastic IP
3	Instance uses Elastic IP	Traffic routed through Elastic IP	Associated	Instance accessible publicly
4	Disassociate Elastic IP	Elastic IP unlinked from instance	Allocated, not associated	Instance loses public IP
5	Release Elastic IP	Elastic IP returned to AWS pool	Released	Instance has private IP only

💡 Elastic IP released back to AWS, no longer associated with any instance.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 4	Final
Elastic IP Status	None	Allocated	Associated	Allocated	Released
Instance Public IP	None	None	Elastic IP assigned	None	None

Key Moments - 3 Insights

Why does the instance lose its public IP after disassociation?

Because the Elastic IP is no longer linked to the instance (see execution_table step 4), the instance reverts to only its private IP.

Can you use an Elastic IP without associating it to an instance?

No, an Elastic IP must be associated with an instance to route traffic (see execution_table step 1 vs step 2).

What happens if you release an Elastic IP without disassociating it first?

AWS automatically disassociates it before releasing, so the Elastic IP becomes free and the instance loses public IP (implied in step 5).

Visual Quiz - 3 Questions

Look at the execution table, what is the Elastic IP status after step 3?

A Allocated, not associated

B Associated

C Released

D Disassociated

💡 Hint

Check the 'Elastic IP Status' column at step 3 in the execution_table.

At which step does the instance lose its public IP?

A Step 4

B Step 2

C Step 3

D Step 5

💡 Hint

Look at the 'Instance IP Status' column in execution_table for when it changes from 'Elastic IP assigned' to 'None'.

If you skip step 4 and directly release the Elastic IP, what happens to the instance's public IP?

A Elastic IP remains associated but unusable

B Instance keeps the Elastic IP

C Instance loses the public IP automatically

D Instance gets a new Elastic IP automatically

💡 Hint

Refer to key_moments about releasing Elastic IP without disassociation.

Concept Snapshot

Elastic IP addresses are static public IPs you allocate from AWS.
You must associate them with an EC2 instance to enable public access.
Disassociating removes the public IP from the instance.
Releasing returns the IP to AWS and frees it for others.
Use Elastic IPs to keep a fixed public IP even if instance stops or restarts.

Full Transcript

Elastic IP addresses in AWS are static public IPs that you can allocate and assign to your EC2 instances. The process starts by requesting an Elastic IP, which AWS reserves for your use. Then you associate this Elastic IP with an EC2 instance, allowing it to be reachable from the internet using that fixed IP. When the instance uses the Elastic IP, all external traffic routes through it. If you disassociate the Elastic IP, the instance loses its public IP and becomes reachable only via its private IP. Finally, releasing the Elastic IP returns it to AWS's pool, making it available for others. This lifecycle ensures you can maintain a consistent public IP for your instance even if it stops or restarts.