IPv4, the foundation of the early internet, has served us well for decades. But the ever-increasing number of devices and services connecting online has led to a shortage of these traditional addresses.
IPv6 steps in as the next-generation solution with a far larger pool of addresses, often making it more cost-effective.
Both accomplish the same thing: being a unique identifier. Just one a bit longer than the other.
But there's also another option, which is combination of both, called Network Address Translation or NAT. It's one of the most popular ways IPs are provisioned for end-consumers nowadays.
What is NAT and why are ISPs relying on it?
As IPv4 addresses become scarce, many ISPs (internet service providers) use NAT to stretch the remaining supply.
NAT allows multiple devices on a private network to share one public IPv4 address. Instead of assigning each device a unique public IPv4 address, NAT routes IPv4 traffic through a shared public IP, usually tracking which data belongs to which device.
Meanwhile, these same devices typically receive their own public IPv6 addresses for direct IPv6 connectivity without translation.
This dual-stack approach helps get more devices online but adds complexity and can make troubleshooting trickier.
Basically, NAT is a temporary measure for IPv4—like adding more seats at a crowded table—rather than a permanent fix, which is why the industry continues to transition toward IPv6.
The promise of IPv6
IPv6 solves the address scarcity problem by providing an enormous address space.
With 2^128 possible addresses (compared to IPv4's 2^32), IPv6 can assign unique public addresses to every networked device on Earth many times over.
Instead of forcing devices to share IPs through NAT, each device gets its own publicly routable IPv6 address.
This enables direct peer-to-peer connections, simplifies network management, and often allows for more efficient routing. IPv6 also includes built-in features like stateless address autoconfiguration (SLAAC) and improved security through mandatory IPsec support.
Note: If you’re looking to tighten security before making the jump, consider reading how to protect your Linux server from brute force attacks with Fail2Ban and 7 quick and easy ways to secure SSH on a Linux server. Good security practices are important no matter which IP version you use.
IPv4 vs. IPv6 addresses
IPv4 addresses use a 32-bit dotted decimal format like 192.168.1.1. IPv6 addresses are 128-bit hexadecimal numbers like 2001:0db8:85a3:0000:0000:8a2e:0370:7334, which can be shortened by removing leading zeros and consecutive zero segments.
The main challenge isn't IPv6's technical capabilities, but rather the ongoing transition from IPv4, as both protocols need to coexist while the internet gradually upgrades.
Comparing IPv4 and IPv6
IPv4 advantages:
- Universal support across devices and networks
- Mature ecosystem of tools, documentation, and expertise
- Well-understood security practices and implementations
IPv4 limitations:
- Depleted address space requiring things like NAT and complex workarounds
- Rising costs for public IPv4 addresses
IPv6 Advantages:
- Virtually unlimited address space eliminates need for NAT
- Built-in support for modern standards, such as IPSec
- More efficient routing with hierarchical addressing
- Lower cost due to abundant supply
IPv6 Challenges:
- Not all network equipment supports IPv6
- Learning curve for network administrators
- Legacy applications may require updates or configuration changes
- Transition period requires managing both protocols simultaneously
Note: For a primer on firewall configuration that can be applied to either IPv4 or IPv6 setups, check out how to easily set up a firewall on Debian with UFW.
Planning your IPv6 migration
Transitioning to IPv6 is best approached gradually through dual-stack networking, where both IPv4 and IPv6 operate simultaneously.
This allows you to:
- Start with a test environment like a development server or VPS
- Configure and test IPv6 connectivity without disrupting existing IPv4 services
- Identify and update applications or services that might need IPv6 support
- Monitor IPv6 traffic patterns and security
- Gradually shift production traffic to IPv6 as confidence grows
Most modern networks operate in dual-stack mode indefinitely, maintaining IPv4 compatibility while leveraging IPv6's advantages. Meaning complete IPv4 retirement typically isn't necessary or practical in the short term, as many services and users still rely on IPv4 connectivity.
The key is starting the IPv6 journey now, even if full adoption takes time.
Begin with understanding your current network topology, making sure your hardware supports IPv6, and planning your IPv6 addressing scheme. Over time, you can phase out IPv4 as you and your applications become IPv6-ready. It doesn't need to happen overnight.
Note: Check out our article on how to find IP addresses (and hide your own) to brush up on networking basics.
How xTom can help
Whether you’re after dedicated servers for complete control, colocation to host your own hardware, or a VPS for quick and scalable deployment, xTom supports both IPv4 and IPv6. Pairing that with xTom’s brokerage services means you can find the right mix of addresses at the right price.
xTom offers IPv4, IPv6, and ASN (Autonomous System Number) services, including leasing, buying, and selling in the following Regional Internet Registries (RIRs):
- RIPE
- APNIC
- ARIN
- AFRINIC
This means you can secure the IP resources you need—IPv4 or IPv6—on terms that make sense for your project.
You can click here to learn more about our IP-related services.
Conclusion
IPv4 laid the groundwork for the internet we know, but its limited supply and rising costs have led to reliance on complex and annoying solutions like NAT.
IPv6 offers a cleaner solution: abundant addresses, simpler routing, and often lower costs for acquiring or leasing addresses. While switching to IPv6 may involve some initial adjustments, the long-term benefits are substantial. It's the future, after all.
Thanks for reading! Hopefully you learned a thing or two about the Internet ;-).