{"id":42247,"date":"2026-09-22T03:46:31","date_gmt":"2026-09-22T10:46:31","guid":{"rendered":"https:\/\/www.privateinternetaccess.com\/blog\/?p=42247"},"modified":"2026-09-22T03:46:45","modified_gmt":"2026-09-22T10:46:45","slug":"ipv4-vs-ipv6","status":"publish","type":"post","link":"https:\/\/www.privateinternetaccess.com\/blog\/ipv4-vs-ipv6\/","title":{"rendered":"Everything You Need to Know About IPv4 vs. IPv6 Right Now"},"content":{"rendered":"\n

Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6) are both network protocols<\/a> that tell internet traffic where it\u2019s going and where it came from. <\/strong>Initially, the developers who created IPv4 thought there would be plenty of addresses to cover every internet-connected device and website. Unfortunately, that wasn\u2019t the case.<\/p>\n\n\n\n

RIPE NCC, the entity responsible for distributing IP addresses in Europe, central Asia, and the Middle East, had run through its pool of 32-bit numeric IPv4 addresses by 2019, so it started using the 128-bit alphanumeric IPv6 addresses to create more potential internet locations.1<\/mn>1<\/annotation><\/semantics><\/math><\/sub> Similar organizations also found themselves in the same predicament.<\/p>\n\n\n\n

There are a variety of technical differences between IPv4 and IPv6 that affect your digital security, network efficiency, and how reliably your devices reach the right destination. But that doesn\u2019t necessarily mean that one protocol is better \u2013 or worse \u2013 than the other.<\/p>\n\n\n

<\/line><\/line><\/line><\/line><\/line><\/line><\/svg>Table of Contents<\/div>5 sections<\/span><\/div>
<\/div>
  1. IPv4 vs. IPv6 At a Glance<\/polyline><\/svg><\/a><\/li>
  2. How IP Addresses Help Internet Communications Work<\/polyline><\/svg><\/a><\/li>
  3. IPv4 vs. IPv6: Which Is Better?<\/polyline><\/svg><\/a><\/li>
  4. Switching from IPv4 to IPv6<\/polyline><\/svg><\/a><\/li>
  5. FAQ<\/polyline><\/svg><\/a><\/li><\/ol><\/div><\/div>\n\n\n

    IPv4 vs. IPv6 At a Glance<\/h2>\n\n\n\n
    Feature<\/strong><\/td>IPv4\u00a0<\/strong><\/td>IPv6<\/strong><\/td><\/tr>
    Address space<\/strong><\/td>About 4.3 billion addresses<\/td>More than 340 undecillion addresses<\/td><\/tr>
    Speed<\/strong><\/td>Neither is faster than the other \u2013 speed depends on network conditions and ISP routing<\/td><\/tr>
    Efficiency<\/strong><\/td>Relies on technologies such as NAT<\/a> to extend the usable address space, adding complexity<\/td>Handles large volumes of traffic more efficiently with simplified headers and native auto-configuration<\/td><\/tr>
    Security<\/strong><\/td>Allows encryption via IPsec, but it\u2019s not built in<\/td>Includes native encryption support via IPsec but doesn\u2019t automatically use it<\/td><\/tr>
    VPN compatibility<\/strong><\/td>Widely supported by VPNs and commonly prioritized over IPv6<\/td>Support varies by provider. VPNs may restrict IPv6 to prevent traffic leaking outside the encrypted tunnel<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    How IP Addresses Help Internet Communications Work<\/h2>\n\n\n\n
    \"\"<\/figure>\n\n\n\n

    Ever wondered how, when you send a message or type a question into a search engine, the message reaches the right destination and the answer finds its way back to your specific device despite hundreds of millions of other connections happening at the same time? That\u2019s all thanks to IP addresses.<\/p>\n\n\n\n

    Although we might think of the internet as one giant interconnected network of devices and websites, it isn\u2019t. It\u2019s actually a network of billions of smaller networks that link together and pass traffic between one another<\/strong>.\u00a0<\/strong><\/p>\n\n\n\n

    To make this setup work, networks assign devices and websites unique IP addresses and break down data into smaller chunks called \u201cpackets.\u201d Every packet carries a source and destination IP address<\/strong>, so the data knows where to go and the receiving device or website knows where to send its response.<\/p>\n\n\n\n

    The internet\u2019s configuration means that there isn\u2019t a single route that these packets need to follow to get from A to Z (or from Z back to A), and an individual router can\u2019t control or predict the packet\u2019s exact path. As information bounces between them, each router reads the destination address and forwards the packet to the next best stop until it arrives.<\/strong><\/p>\n\n\n\n

    This usually works behind the scenes, but if any part of this addressing goes wrong or there\u2019s an address in the chain that the network can\u2019t reach, messages go undelivered and 404 pages start popping up.<\/p>\n\n\n\n

    IPv4 vs. IPv6 Address Evolution<\/h3>\n\n\n\n

    IPv4 was the first version of the Internet Protocol built for public, everyday use.<\/strong> Its 32-bit structure put the address pool at roughly 4.3 billion unique addresses, which felt more than generous when engineers settled on it in the early 1980s.<\/p>\n\n\n\n

    However, when personal computers and the broader internet skyrocketed to mainstream popularity in the 1990s and millions of new devices went online each year, it became clear that IPv4 wouldn\u2019t be as long-lasting as anticipated.\u00a0<\/p>\n\n\n\n

    Engineers needed to accommodate a much larger number of devices and websites, which is exactly what Internet Protocol version 6 (IPv6) provides.<\/strong><\/p>\n\n\n\n

    IPv6\u2019s 128-bit alphanumeric structure supports over 340 undecillion addresses <\/strong>(that\u2019s 340 trillion trillion trillion, or 340 followed by 34 zeros), <\/strong>roughly 1028<\/sup> times as many as IPv4 offers.<\/p>\n\n\n\n

    What Happened to IPv5?<\/h4>\n\n\n\n

    There\u2019s lots of guidance about IPv6 vs. IPv4 online. But IPv5, which should sit between these two, barely gets a mention.\u00a0<\/p>\n\n\n\n

    The reason is that IPv5 is not available for public use.<\/strong> Designed to carry real-time voice and video traffic rather than general internet data, engineers assigned the number 5 to an experimental protocol called the Internet Stream Protocol (ST).<\/p>\n\n\n\n

    The ST never made it past a limited, experimental deployment. When the successor to IPv4 was ready, developers skipped straight to IPv6 to avoid any confusion with the ST version.<\/p>\n\n\n\n

    IPv4 vs. IPv6: Which Is Better?<\/h2>\n\n\n\n

    Neither protocol is outright better than the other.<\/strong> Both are responsible for conveying information across the internet but each does that in a different way, creating different benefits and drawbacks.<\/p>\n\n\n\n

    IPv4 and IPv6: Head-to-Head Comparison\u00a0<\/h3>\n\n\n\n

    IPv4 and IPv6 are part of the Transmission Control Protocol (TCP)<\/a>, <\/strong>and both break data into smaller packets to move it across the internet. But that\u2019s where the similarities end.<\/p>\n\n\n\n

    The two protocols diverge in how they\u2019re structured, how much translation and configuration they need, and how well they scale for a world where almost every household item can have its own internet connection.<\/p>\n\n\n\n

    Characteristic<\/strong><\/td>IPv4<\/strong><\/td>IPv6<\/strong><\/td><\/tr>
    Address size<\/strong><\/td>32-bit, about 4.3 billion addresses<\/td>128-bit, over 340 undecillion addresses<\/td><\/tr>
    Naming standard<\/strong><\/td>Dotted-decimal notation (e.g. 192.168.1.1)<\/td>Hexadecimal, colon-separated (e.g. 2001:db8::1)<\/td><\/tr>
    Address translation<\/strong><\/td>Relies on NAT to share limited public addresses<\/td>Rarely needed; large address pool supports direct addressing<\/td><\/tr>
    Packet addressing<\/strong><\/td>Unicast, broadcast, multicast<\/td>Unicast, anycast, multicast (no broadcast)<\/td><\/tr>
    Address configuration<\/strong><\/td>Manual or DHCP-assigned<\/td>Stateless autoconfiguration (SLAAC) or DHCPv6<\/td><\/tr>
    Fragmentation<\/strong><\/td>Can happen at the source or at routers along the path<\/td>Only the source device can fragment while routers drop oversized packets instead<\/td><\/tr>
    DNS resolution<\/strong><\/td>Uses A records<\/td>Uses AAAA records<\/td><\/tr>
    Privacy<\/strong><\/td>Devices often share one visible address via NAT<\/td>Each device usually gets its own address; privacy extensions rotate it periodically<\/td><\/tr>
    Efficiency<\/strong><\/td>Needs NAT and other workarounds to stretch limited addresses<\/td>Simplified header and native features reduce processing overhead<\/td><\/tr>
    Mobile support<\/strong><\/td>Works, but NAT and address changes can complicate handoffs<\/td>Built-in support and abundant addresses ease handoffs between networks<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    None of IPv6\u2019s features make it inherently faster or more secure than IPv4.<\/strong> Speed still depends on your routing path, your ISP network quality, and how many hops your traffic takes to reach its destination, regardless of which protocol carries it.\u00a0<\/p>\n\n\n\n

    Security works the same way: <\/strong>Firewalls<\/a>, network segmentation, monitoring, and careful configuration matter more than the protocol version you\u2019re using. A poorly configured IPv6 network can be as exposed as an outdated IPv4 one, and a well-managed IPv4 network can hold up fine against most everyday threats.<\/p>\n\n\n\n

    How IPv4 Works<\/h3>\n\n\n\n
    \"IPv4<\/figure>\n\n\n\n

    An IPv4 address uses four numbers between 0 and 255, separated by periods (e.g. 192.0.2.1).<\/strong> Each of those numbers represents 8 bits, adding up to the full 32-bit address.\u00a0<\/p>\n\n\n\n

    When you type a website address into your browser, an A record in the Domain Name System (DNS)<\/a> translates that human-readable address into its IPv4 address so your device knows where to send the request.<\/p>\n\n\n\n

    There are three ways this traffic can be addressed with IPv4 and the method depends on how many devices receive the communication:\u00a0<\/p>\n\n\n\n