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 \u2014 while availability keeps shrinking \u2014 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.<\/p>\n
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 \u2014 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\u2013$50+ in recent years.<\/p>\n
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 \u2014 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.<\/p>\n
Since February 2024, AWS bills every public IPv4 address $0.005\/hour (roughly $3.60\/month) \u2014 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\u201330 public IPs before a single user has connected.<\/p>\n
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.<\/p>\n
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.<\/p>\n
| Provider<\/th>\n | Public IP Charge<\/th>\n | Idle IP Charge<\/th>\n | BYOIP Supported<\/th>\n<\/tr>\n<\/thead>\n |
|---|---|---|---|
| AWS<\/td>\n | ~$3.60\/month per IP<\/td>\n | ~$3.60\/month<\/td>\n | Yes (min \/24, per region)<\/td>\n<\/tr>\n |
| Azure<\/td>\n | ~$3.65\/month per static IP<\/td>\n | Billed while reserved<\/td>\n | Yes (custom IP prefix)<\/td>\n<\/tr>\n |
| GCP<\/td>\n | ~$3.60\/month per static IP<\/td>\n | ~$7.30\/month idle<\/td>\n | Yes (min \/24, per region)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n Key insight:<\/strong> At scale, provider IP charges are a recurring cost \u2014 but owning your own block converts that spend into an appreciating asset you can port across all three clouds.<\/div>\n Allocation Strategies That Work<\/h2>\nUsing Your Own IPv4 Space (BYOIP)<\/h2>\nAll 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?<\/p>\n
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