IPv4 Shortage: Why Enterprises Turn to SASE and Cloud NAT

The IPv4 shortage isn’t going anywhere in 2025. Network architects keep getting pulled into the same conversation: pay through the nose for addresses, or redesign around SASE and cloud NAT and sidestep the problem entirely. The five Regional Internet Registries ran dry years ago, secondary market prices keep creeping upward, and organizations that once treated public IPv4 as cheap plumbing now face a genuinely strategic call. Buy, lease, or rebuild?

Why the IPv4 Shortage Keeps Escalating in 2025

Several forces are compounding the shortage rather than relieving it. Device growth keeps marching on—IoT deployments, 5G rollouts, edge computing, all of it hungry for routable addressing. Hyperscale cloud providers and large CDNs are soaking up significant blocks to fuel their own expansion, which quietly drains inventory from the open market. And legacy holders—universities, corporations sitting on Class B-era allocations—are holding rather than selling, betting prices go higher still.

Then there’s IPv6, the supposed silver bullet. Adoption remains uneven at best. Major content providers report hefty IPv6 traffic shares, sure, but enterprise internal networks and plenty of regional ISPs still lag behind, which means dual-stack operations need IPv4 addresses on both ends of most connections anyway. The practical upshot? Even IPv6-forward organizations need translation or NAT64 infrastructure, and that infrastructure itself benefits from dedicated public space. A bit ironic, isn’t it.

• RIPE NCC and ARIN waitlists remain years long for new allocations.
• Returned/reclaimed blocks are tiny relative to demand.
• Geopolitical routing restrictions complicate cross-RIR transfers.

The True Cost of Acquiring IPv4 Addresses Today

Secondary market pricing has settled in the $40–$60 per-address range for clean, RIR-transferable blocks. That puts a modest /24 at roughly $10,000–$15,000 before transaction costs. But the sticker price badly understates total cost of ownership:

1. Broker and escrow fees — typically 5–15% of transaction value.
2. RIR transfer processing — administrative fees plus approval timelines stretching from weeks to months.
3. Due diligence — verifying the block is clean of blacklisting, hijack history, and competing claims. This step matters more than people assume.
4. Ongoing management — SWIP/WHOIS accuracy requirements, RPKI ROA provisioning, and abuse-response readiness.

Leasing is the alternative: roughly $0.30–$0.60 per address per month. Fine for seasonal capacity or short-lived projects, but past the three-to-five-year mark it costs more than buying outright. Whichever route you take, work with a marketplace that performs verified seller checks, blacklist screening, and secure escrow. Platforms like IP4 Market specialize in exactly this, and it shows—private IPv4 transactions have a long history of going sideways when nobody’s vetted the other side.

How SASE Reduces Enterprise Reliance on Public IPv4

Secure Access Service Edge changes the addressing equation at a structural level. Under the traditional model, every branch office, data center egress, and remote-access gateway needs public IPv4 space for direct connectivity. Under SASE, traffic from users and branches tunnels to provider points of presence—and only the provider’s shared infrastructure burns public addresses.

Picture a retail enterprise with 500 branches. A legacy WAN might consume two to four public /24s across firewalls and VPN concentrators. Move to a SASE platform (Zscaler, Netskope, Cloudflare One, or similar) and that footprint collapses to essentially zero at the branch level, because SD-WAN edges initiate outbound tunnels to cloud PoPs. Cloud NAT services—AWS NAT Gateway, Azure NAT Gateway, Google Cloud NAT—do something similar for workloads, letting them reach the internet through provider-managed public IPs with no per-instance addressing at all.

The trade-offs deserve honest treatment, though. SASE subscription costs per user or site can rival IPv4 acquisition costs for smaller estates, and egress through shared provider IPs makes allowlisting messy. Enterprises with partner integrations or regulatory requirements for static, dedicated egress addresses may still need a small owned block—often just a /24 sourced through a verified marketplace—paired with cloud NAT or SASE for everything else. Which points at the emerging best practice: hybrid. Minimize owned IPv4 to what compliance genuinely demands, and let SASE and managed NAT absorb the rest.

Cloud NAT and Shared IP Strategies for Scalable Networking

Cloud NAT services offered by AWS, Azure, and Google Cloud allow thousands of private instances to share a small pool of public addresses. The numbers speak for themselves. A single regional NAT gateway can egress tens of gigabits per second while consuming fewer than a dozen IPv4 addresses, which makes it one of the most efficient responses to the shortage for outbound workloads.

Some practical tips from real deployments:

• Right-size port allocation: AWS NAT gateways support roughly 64,000 simultaneous connections per IP. Estimate per-instance connection counts before deciding how many addresses to attach, and keep an eye on SNAT port exhaustion metrics — when they spike, connections start failing in ways that are painful to debug.
• Separate egress tiers: Route bulk outbound traffic (patching, updates, API calls) through shared NAT. Reserve dedicated IPs for services with reputation-sensitive requirements, email being the classic example, or payment integrations.
• Leverage cloud provider shared pools: For workloads without strict IP governance requirements, using provider-owned shared addresses eliminates your address footprint entirely. Simple as that.

Hybrid enterprises can apply the same logic on-premises, by the way. Centralizing internet egress through carrier-grade NAT (CGNAT) with private RFC 1918 addressing internally conserves public space for the workloads that genuinely need it.

IPv4 Shortage Workarounds: Comparing SASE, Cloud NAT, and Leasing

Each mitigation strategy addresses a different facet of the problem, and most organizations end up combining them. The question isn’t which one wins — it’s which one fits which piece of your network.

• SASE: Best for user-to-application connectivity. By terminating traffic at provider edges, SASE removes the need for per-branch or per-user public addresses. Trade-offs? Subscription costs and reliance on provider routing.
• Cloud NAT: Best for server egress in cloud environments. Predictable pricing, elastic scaling, and no address ownership burden. The limitation shows up with inbound services, which still need dedicated IPs.
• Leasing IPv4 blocks: Best for inbound-facing workloads, ASN announcements, and geo-restricted services. Leasing preserves capital versus purchasing, with typical market rates ranging from $0.30 to $0.60 per IP monthly. Read the contract carefully — it should cover clean reputation, RPKI authorization, and clear termination terms.

Conclusion: Building an IP-Efficient Network Strategy

The IPv4 shortage is no longer a future risk. It’s a structural condition of the internet, one that pricing, scarcity, and broker activity all confirm. Enterprises that respond strategically rather than reactively gain both cost control and architectural agility.

A resilient roadmap looks like this:

1. Audit current address utilization and reclaim unused allocations first.
2. Adopt SASE for user connectivity to eliminate branch and remote-worker address needs.
3. Consolidate cloud egress through managed NAT services with monitored port capacity.
4. Acquire only the minimum owned or leased IPv4 space required for compliance and inbound services.

Executed together, these steps can reduce an enterprise’s address requirements by 80 percent or more while improving security posture through centralized inspection and zero-trust access. And when the time comes to buy or lease that essential block, working with a trusted marketplace such as IP4 Market ensures verified sellers, clean IP reputation, and fair market pricing. The organizations that master IP efficiency today will be the ones best positioned for the transition to IPv6 tomorrow.