Companies that hold Class B IPv4 address space (historically defined as 128.0.0.0 to 191.255.255.255) often face unique challenges in today’s internet landscape. While Class B allocations originally provided up to 65,536 IP addresses, modern network demands, IPv4 scarcity, and evolving policies mean that organizations must rethink how they use, expand, or restructure their Class B resources.
Whether your company still operates a legacy Class B block or needs additional IPv4 space to support growth, there are multiple solutions available in 2025. This guide explores the best IPv4 strategies for companies with Class B addresses, including optimization, expansion, buying, selling, and leasing.
Understanding Class B IPv4 Addresses in Today’s Market
In the early internet era, Class B networks were assigned to universities, corporations, government organizations, and technology firms. These blocks were extremely valuable because they offered large, flexible address space.
However, today:
- The original classful system is obsolete.
- Routing is classless (CIDR-based).
- IPv4 scarcity has made Class B ranges highly valuable.
- Many organizations no longer need their entire allocation.
- Companies with legacy Class B blocks may be sitting on assets worth millions.
Because modern infrastructure is designed using CIDR, Class B blocks are typically broken into /16, /17, /18, and smaller subnet ranges depending on business needs.
1. Optimize or Reallocate Your Existing Class B Space
If your organization holds a Class B legacy block, the first and often most cost-effective solution is to optimize that space.
Modern subnetting
Dividing a Class B block into smaller CIDR ranges helps ensure efficient usage.
Reclaiming unused subnets
Many older networks have entire segments unused or misallocated.
Migrating to modern routing equipment
Newer systems support better traffic handling, security, and IP management. Internal audits
Determine how much of your Class B space is active, reserved, or wasted.
Many companies discover they are using only a fraction of their Class B allocation, opening opportunities for leasing or selling unused ranges.
2. Lease Out Unused Class B IPv4 for Monthly Revenue
If you hold more IPv4 than you need, leasing is a powerful solution that turns unused IPs into consistent profit.
Benefits of leasing Class B space:
- Recurring monthly income
- Retain ownership of your legacy block.
- No need for permanent transfer
- High demand from hosting providers and VPN services
- Easy management through a trusted IPv4 broker
A Class B /16 block contains 65,536 addresses, meaning even partial leasing can generate substantial revenue.
3. Sell Unused Class B IPv4 Blocks for Major Profit
Because IPv4 scarcity is increasing, Class B address blocks sell at premium prices. Blocks with clean reputation and correct documentation are among the highest-valued assets in the IPv4 market.
Selling unused ranges enables companies to:
- Unlock significant capital
- Fund modernization or cloud migration
- Eliminate maintenance and compliance overhead.
- Increase operational efficiency
IPv4 Hub assists organizations in securely selling clean Class B address ranges with full transfer management and escrow protection.
4. Buy Additional IPv4 Space to Support Growth
Some companies with Class B blocks still require more IPv4 due to:
- New services or applications
- Customer expansion
- Multi-region deployments
- SaaS platform scaling
- Datacenter or cloud infrastructure growth
If your Class B space cannot support long-term expansion, buying additional IPv4 blocks is the most stable solution.
IPv4 Hub offers verified, clean IPv4 ranges of all sizes, including:
- /24 for small deployments
- /23, /22 for medium networks
- /21 to /18 for scaling infrastructures
All purchases include blacklist checking, seller verification, and RIR-compliant transfers.
5. Use NAT and IPv6 Integration for Sustainability
Even companies with Class B addresses benefit from hybrid solutions:
Network Address Translation (NAT)
Allows many internal devices to share fewer public IPs.
Dual-stack IPv4 + IPv6 deployments
Ensures compatibility and future-proofing.
Gradual IPv6 migration plans
Reduces long-term reliance on IPv4.
These strategies help maximize your Class B usage and reduce pressure to acquire additional blocks.
6. Protect Your Class B Assets with Proper Management
Large IPv4 holdings require professional care:
- Keep WHOIS records accurate.
- Monitor block reputation regularly.
- Secure routing announcements (RPKI/IRR)
- Use geolocation correction tools.
- Work with reputable brokers for all transactions.
IPv4 Hub provides reputation checks, routing guidance, and secure management support.
Class B IPv4 Blocks Are Valuable. Use Them Wisely
Companies holding Class B IPv4 address space are in a powerful position. These legacy blocks provide flexibility, financial opportunity, and network stability. But they must be managed strategically.
Whether you want to scale your infrastructure, lease unused space, sell for profit, or acquire more IPv4, IPv4 Hub delivers the tools, guidance, and security you need to maximize the value of your assets.