Multi-Region Cloud IPv4 Allocation: AWS, Azure, GCP Guide

Ask anyone who has run infrastructure across more than one cloud region and they’ll tell you the same thing: nobody plans IPv4 until it starts costing real money. Then it costs a lot of it. Public IP space gets consumed by every region you deploy into, and with prices climbing year after year — while availability keeps shrinking — a sloppy allocation strategy quietly burns thousands of dollars annually in wasted addresses and hourly charges. What follows is how network engineers and IT managers can allocate IPv4 sensibly across AWS, Azure, and GCP.

Why Multi-Region Cloud IPv4 Planning Matters

Here’s the uncomfortable math. Every region multiplies your public IP consumption. A load balancer in three regions, NAT gateways in each availability zone, failover infrastructure standing by — all of it draws from the same finite global pool. And that pool has been effectively dry since IANA exhausted its free space in 2011; the regional registries followed soon after. New addresses now come almost exclusively from the secondary market, where per-address prices have climbed from under $20 in 2019 to $35–$50+ in recent years.

What does poor planning actually look like in practice? Usually one of three things. Address exhaustion, which forces an emergency purchase at premium prices. Fragmentation — scattered /32s you can’t aggregate or route efficiently. Or cost leakage: idle Elastic IPs billing month after month with zero workloads attached. I’ve seen all three. Often in the same environment.

How Each Provider Consumes IPv4

AWS

Since February 2024, AWS bills every public IPv4 address $0.005/hour (roughly $3.60/month) — including addresses attached to running EC2 instances. NAT Gateways take an Elastic IP per AZ. Network Load Balancers consume static IPs per subnet. Do the arithmetic on a three-AZ, three-region architecture and you can easily burn through 20–30 public IPs before a single user has connected.

Azure

Azure charges for static public IPs (Standard SKU, roughly $0.005/hour) and requires them for Standard Load Balancers, NAT Gateways, and VPN gateways. One wrinkle worth knowing: regional and global IP addresses behave differently, and global-tier IPs for cross-region load balancing are billed at a premium.

GCP

Google Cloud charges for static in-use and idle external IPs alike (approximately $0.005/hour in-use, more when idle). The interesting bit is Cloud NAT: it uses ports on assigned IPs rather than one IP per instance, which makes GCP the most IP-efficient of the three for outbound traffic at scale.

IPv4 Costs Compared

Allocation Strategies That Work

1. Centralize egress. NAT gateways or Cloud NAT let thousands of private instances share a handful of public IPs instead of burning one per instance. Obvious? You’d be surprised how often it’s skipped.
2. Size CIDR blocks generously. Reserve /24s — the minimum portable, routable block on the internet — per region, rather than scattering /28s you’ll outgrow in six months.
3. Prefer IPv6 dual-stack. Front-end services with IPv6 where you can, to shave public IPv4 demand off load balancers and CDNs.
4. Use shared IPs for failover. Global load balancers (AWS Global Accelerator, Azure Cross-Region LB, GCP Global Anycast) let one or two anycast IPs serve all your regions.
5. Audit idle addresses monthly. Tag them, alert on them. Unattached IPs are pure waste — there’s no other way to put it.

Using Your Own IPv4 Space (BYOIP)

All three hyperscalers support Bring Your Own IP. The mechanics: you transfer a block (typically /24 or larger) to a cloud-hosted account, advertise it via BGP from your own ASN or the provider’s, then use it natively across regions. What do you get for the effort?

• Reputation and allowlisting that travels with you — critical for email sending and API integrations
• No hourly public IP charges on BYOIP addresses
• Freedom to migrate between clouds without re-addressing everything
• A tangible asset that has historically appreciated

Acquiring a clean /24 takes real due diligence. Verify the block has no blacklisting history, check RPKI readiness, confirm clean WHOIS records, and make sure the transfer goes properly through a Regional Internet Registry (ARIN, RIPE, APNIC, LACNIC, or AFRINIC). This is where a trusted marketplace earns its keep — IP4 Market offers verified sellers, escrow-protected transfers, and competitive pricing, which makes it a reliable channel for procuring IPv4 blocks suitable for BYOIP deployments.

Best Practices and Common Mistakes

Do

• Document every allocated prefix with owner, region, and purpose in IPAM (NetBox, phpIPAM, or Infoblox)
• Plan for a 3–5 year growth horizon when reserving blocks
• Consolidate to /24-aligned blocks for clean BGP announcements
• Watch regional IP quotas proactively — request increases before they block a deployment, not after

Don’t

• Split scarce space into tiny subnets that can’t be aggregated
• Leave idle Elastic IPs, reserved Azure IPs, or static GCP addresses unmonitored
• Buy addresses reactively during an outage. Scarcity pricing punishes urgency, every time.

FAQ

A disciplined multi-region IPv4 strategy comes down to a few habits: centralized egress, generous CIDR sizing, BYOIP ownership, and continuous auditing. Whether you’re acquiring your first /24 or squeezing allocation across dozens of regions, treating IPv4 as a strategic asset rather than an afterthought will save you cost and headaches for years.