{"id":6846,"date":"2025-02-25T11:36:02","date_gmt":"2025-02-25T11:36:02","guid":{"rendered":"https:\/\/www.ktchost.com\/blog\/?p=6846"},"modified":"2025-02-26T11:37:55","modified_gmt":"2025-02-26T11:37:55","slug":"what-is-an-elastic-ip-address-in-aws","status":"publish","type":"post","link":"https:\/\/www.ktchost.com\/blog\/what-is-an-elastic-ip-address-in-aws\/","title":{"rendered":"What is an Elastic IP address in AWS?"},"content":{"rendered":"\n

An Elastic IP (EIP)<\/strong> address in AWS is a static, public IPv4 address<\/strong> that you can allocate and assign to an EC2 instance. Unlike a regular public IP that changes when an instance is stopped and restarted, an Elastic IP remains constant<\/strong>, allowing you to maintain a fixed address for your applications.<\/p>\n\n\n\n

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Why Use an Elastic IP?<\/strong><\/h2>\n\n\n\n

By default, AWS assigns a dynamic public IP<\/strong> to an EC2 instance when it is launched. However, this IP changes every time you stop and start<\/strong> the instance.<\/p>\n\n\n\n

\ud83d\udd39 Problem:<\/strong> If for example your Application blog is hosted on an EC2 instance with a dynamic public IP, every time you restart the instance, the IP changes, causing disruptions.<\/p>\n\n\n\n

\ud83d\udd39 Solution:<\/strong> An Elastic IP<\/strong> ensures that your Application site always has the same public IP, avoiding frequent DNS updates or reconfigurations.<\/p>\n\n\n\n

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Key Features of Elastic IPs<\/strong><\/h2>\n\n\n\n
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  1. Static & Persistent<\/strong> \u2013 Unlike normal public IPs, an Elastic IP doesn\u2019t change when the instance is stopped or restarted.<\/li>\n\n\n\n
  2. Reassignable<\/strong> \u2013 You can detach an Elastic IP from one instance and attach it to another without changing the IP.<\/li>\n\n\n\n
  3. Charges Apply If Unused<\/strong> \u2013 AWS provides one free Elastic IP per account<\/strong> as long as it\u2019s associated with a running instance. However, unused Elastic IPs incur charges<\/strong>.<\/li>\n<\/ol>\n\n\n\n
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    How to Allocate and Associate an Elastic IP<\/strong><\/h2>\n\n\n\n

    Step 1: Allocate an Elastic IP<\/strong><\/h3>\n\n\n\n
      \n
    1. Open the AWS Management Console<\/strong>.<\/li>\n\n\n\n
    2. Navigate to EC2 Dashboard<\/strong> \u2192 Elastic IPs<\/strong> (under Network & Security).<\/li>\n\n\n\n
    3. Click on Allocate Elastic IP Address<\/strong>.<\/li>\n\n\n\n
    4. Choose Amazon\u2019s pool of IPv4 addresses<\/strong> and click Allocate<\/strong>.<\/li>\n\n\n\n
    5. You will now have an Elastic IP<\/strong> allocated to your account.<\/li>\n<\/ol>\n\n\n\n

      Step 2: Associate the Elastic IP with an EC2 Instance<\/strong><\/h3>\n\n\n\n
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      1. Select the newly allocated Elastic IP.<\/li>\n\n\n\n
      2. Click Actions<\/strong> \u2192 Associate Elastic IP Address<\/strong>.<\/li>\n\n\n\n
      3. Choose your EC2 instance<\/strong> from the list.<\/li>\n\n\n\n
      4. Click Associate<\/strong>.<\/li>\n<\/ol>\n\n\n\n

        Now, your EC2 instance has a fixed, static public IP<\/strong> that will not change even if the instance is stopped and restarted.<\/p>\n\n\n\n

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        Example Scenario: Hosting a Application with Elastic IP<\/strong><\/h2>\n\n\n\n

        Without Elastic IP<\/strong><\/h3>\n\n\n\n

        \ud83d\udd38 You launch an EC2 instance<\/strong> to host your Application.
        \ud83d\udd38 AWS assigns a dynamic public IP<\/strong> (e.g., 54.200.120.50<\/code>).
        \ud83d\udd38 You map your domain (your-application.com<\/code>) to this IP.
        \ud83d\udd38 Later, you restart<\/strong> the instance, and AWS assigns a new public IP (e.g., 3.85.220.40<\/code>).
        \ud83d\udd38 Now, your website is inaccessible until you update the DNS settings with the new IP.<\/p>\n\n\n\n

        With Elastic IP<\/strong><\/h3>\n\n\n\n

        \u2705 You allocate an Elastic IP<\/strong> (e.g., 18.220.50.80<\/code>) and associate it with your EC2 instance.
        \u2705 You map your domain (your-application.com<\/code>) to this Elastic IP.
        \u2705 Even if you restart the instance<\/strong>, the Elastic IP remains unchanged<\/strong>.
        \u2705 Your Application remains accessible without any DNS changes<\/strong>.<\/p>\n\n\n\n

        \n\n\n\n

        How to Release an Elastic IP (If No Longer Needed)<\/strong><\/h2>\n\n\n\n

        If you no longer need an Elastic IP, follow these steps to avoid unnecessary charges<\/strong>:<\/p>\n\n\n\n

          \n
        1. Disassociate the Elastic IP<\/strong> from the instance.\n