Internet Protocol version 4 (IPv4) is the fourth revision in the development of the Internet Protocol (IP) and the first version of the protocol to be widely deployed. Together with IPv6, it is at the core of standards-based internetworking methods of the Internet. IPv4 is still, by far, the most widely deployed Internet Layer protocol. Internet Protocol version 6 (IPv6) is a version of the Internet Protocol (IP) that is designed to succeed Internet Protocol version 4 (IPv4). The Internet operates by transferring data in small packets that are independently routed across networks as specified by an international communications protocol known as the Internet Protocol. Although IPv4 is still the most commonly used protocol, I want to list the differences between both so you can better understand why your company and ISP must begin making plans to migrate to IPv6.
IPv4 has run out of IP addresses.
IPv4
- Addresses are 32 bits (4 bytes) in length.
- Address (A) resource records in DNS to map host names to IPv4 addresses.
- Pointer (PTR) resource records in the IN-ADDR.ARPA DNS domain to map IPv4 addresses to host names.
- IPSec is optional and should be supported externally
- Header does not identify packet flow for QoS handling by routers
- Both routers and the sending host fragment packets.
- Header includes a checksum.
- Header includes options.
- ARP uses broadcast ARP request to resolve IP to MAC/Hardware address.
- Internet Group Management Protocol (IGMP) manages membership in local subnet groups.
- Broadcast addresses are used to send traffic to all nodes on a subnet.
- Configured either manually or through DHCP.
- Must support a 576-byte packet size (possibly fragmented).
IPv6 is the successor to IPv4, but deployment has been slow.
IPv6
- Addresses are 128 bits (16 bytes) in length
- Address (AAAA) resource records in DNS to map host names to IPv6 addresses.
- Pointer (PTR) resource records in the IP6.ARPA DNS domain to map IPv6 addresses to host names.
- IPSec support is not optional
- Header contains Flow Label field, which Identifies packet flow for QoS handling by router.
- Routers do not support packet fragmentation. Sending host fragments packets
- Header does not include a checksum.
- Optional data is supported as extension headers.
- Multicast Neighbor Solicitation messages resolve IP addresses to MAC addresses.
- Multicast Listener Discovery (MLD) messages manage membership in local subnet groups.
- IPv6 uses a link-local scope all-nodes multicast address.
- Does not require manual configuration or DHCP.
- Must support a 1280-byte packet size (without fragmentation).
Depending on what you are using, the IP address for either version is still valid. There are some advantages to upgrading from IPv4 to IPv6 such as 79 octillion (that’s 27 zeros) times the IPv4 address space, better bandwidth efficiency, better efficiency and scalability, and works with the latest 3G mobile technologies and beyond. With so many devices requiring IP addresses for Internet access, the development of a more versatile Internet Protocol was inevitable. I hope this article helps you better understand the differences between IPv4 and IPv6 so that you can make your decision accordingly.
Juniper Networks describes in layman’s terms on a video in their YouTube channel the need for creating an IPv6 migration strategy.
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