AWS introduced new public IPv4 pricing in 2024:

$0.005 per hour per public IPv4 = $3.60/month each
Applies whether the IP is Elastic or directly attached to an EC2.
This cost is in addition to your EC2, VPC, and data transfer charges.

If you run multiple domains or services on AWS, these charges add up quickly. Below is a step-by-step cost reduction playbook.

🔹 1. Consolidate Domains on Fewer Public IPs

Instead of assigning 1 IP per domain, you can serve multiple domains from a single IP using Virtual Hosts in Apache/Nginx.

Example: Apache VirtualHosts

<VirtualHost *:80>
    ServerName domain1.com
    DocumentRoot /var/www/domain1
</VirtualHost>

<VirtualHost *:80>
    ServerName domain2.com
    DocumentRoot /var/www/domain2
</VirtualHost>

<VirtualHost *:80>
    ServerName domain3.com
    DocumentRoot /var/www/domain3
</VirtualHost>

Point all DNS records (A or CNAME) to the same EC2 public IP.
The web server selects the right site based on the Host header.
Savings: 3 IPs → 1 IP = cut IPv4 cost by 66% (from $11.16 to $3.72/month).

🔹 2. Use Application Load Balancer (ALB)

ALB provides a single DNS name (e.g., myapp-1234567890.ap-south-1.elb.amazonaws.com).
Supports host-based routing:
- domain1.com → target group 1
- domain2.com → target group 2
You don’t need any public IPs on EC2 (only private IPs in private subnets).
ALB has a fixed hourly + LCU cost (~$16–$18/month), so it’s cost-effective if:
- You manage 5+ domains.
- You want SSL offloading, WAF, auto-scaling.

🔹 3. Put Domains Behind CloudFront CDN

CloudFront distributions don’t charge per IP.
Each distribution gets a public edge DNS name (e.g., dxxxxx.cloudfront.net).
Attach your custom domains via CNAME + ACM certificate.
CloudFront forwards traffic to your EC2 instance’s private IP or ALB.
You can consolidate dozens of domains behind CloudFront, all with zero IPv4 cost.

🔹 4. Embrace IPv6 (Free)

AWS charges for IPv4, but IPv6 is free.
Steps:
- Enable dual-stack networking for EC2/ALB/CloudFront.
- Add AAAA DNS records for your domains.
- Encourage users/CDNs/ISPs to connect via IPv6.
You’ll still need at least 1 IPv4 for compatibility, but gradually traffic shifts away.

🔹 5. Release Idle Elastic IPs

Check for unused Elastic IPs: aws ec2 describe-addresses --query "Addresses[?AssociationId==null]"
Release them: aws ec2 release-address --allocation-id eipalloc-xxxxxx
AWS charges for unattached Elastic IPs, so don’t keep them reserved if not in use.

🔹 6. Use DNS Instead of IPs for Apps

Many setups bind services directly to public IPs.
Instead, use Route 53 (or any DNS provider) and map domain → single public endpoint.
This avoids the “1 IP per service” trap.

🔹 7. Automate Audit & Alerts

Enable AWS Cost Explorer + Budgets:
- Track IPv4 cost (Amazon Virtual Private Cloud → Public IPv4 Address line item).
- Set alerts if IPv4 spend > $5–$10.
Run a weekly script to list public IP usage: aws ec2 describe-instances --query "Reservations[*].Instances[*].[InstanceId,PublicIpAddress]" --output table

✅ Summary of Optimization Options

Strategy	Effort	Savings	Best For
VirtualHosts (1 IP, many domains)	Easy	High (66–80%)	Small setups, 2–10 domains
Release unused IPs	Easy	Small (~$3.60/IP/mo)	Anyone with idle Elastic IPs
ALB (DNS-based routing)	Medium	Moderate	Multi-domain, need SSL/WAF/scaling
CloudFront (CDN)	Medium	High (remove all IPv4 costs, reduce egress too)	Global traffic, static assets
IPv6 adoption	Medium/Long	Future-proof	Long-term savings, modern apps

📌 Recommended Path (for your case)

Since you said 3 domains → 3 EC2 public IPs:

✅ Switch all 3 domains to 1 EC2 public IP (via Apache VirtualHosts).
✅ Release the 2 extra Elastic IPs.
Later, move everything behind CloudFront → $0 IPv4 charge + huge egress savings.
Enable IPv6 dual-stack now to future-proof.

👉 This way your IPv4 cost drops from $11.16 → $3.72 now, and eventually $0.

AWS Cost Optimization for Public IPv4 Addresses