IPv6 support

Select Digi products support Internet Protocol version 6 (IPv6), electronic devices use this network layer standard to exchange data across a packet-switched network. IPv6 is provides more addresses for networked devices than IPv4.

The primary change from IPv4 to IPv6 is the length of network addresses. IPv4 address are 32 bits long. In contrast, IPv6 addresses are 128 bits long and are typically composed of two logical parts: a 64-bit network prefix and a 64-bit host part, which is either automatically generated from the interface’s MAC address or assigned sequentially.

IPv6 addresses are normally written as eight groups of four hexadecimal digits. For example: 3002:0ff2:63a5:0db8:42ae:0040:02de:3560. You can omit leading zeros in a group. If a four-digit group is 0000, the zeros may be omitted, and that part of the address shortened to two consecutive colons, provided you use only one double colon in the address. You can write a sequence of four bytes at the end of an IPv6 address in decimal, using dots as separators.

IPv6 networks are written using CIDR notation.

An IPv6 network (or subnet) is a contiguous group of IPv6 addresses the size of which must be a power of two; the initial bits of addresses which are identical for all hosts in the network are called the network's prefix.

A network is denoted by the first address in the network and the size in bits of the prefix, separated with a slash. For example, 2001:1234:5678:9ABC::/64 stands for the network with addresses 2001:1234:5678:9ABC:: through 2001:1234:5678:9ABC:FFFF:FFFF:FFFF:FFFF.

Because you can see a single host as a network with a 128-bit prefix, you will sometimes see host addresses written followed with /128.

Implementation of IPv6 in Digi products means that there are more ways in which you can express addresses for devices and destinations:

• As an IPv4 address, for example 10.8.118.3.
• As an IPv6 address in any of its accepted notation formats, including address notation with special meanings, for example, 3002:0ff2:63a5:0db8:42ae:0040:02de:3560,
• As a Fully Qualified Domain Name (FQDN), for example www.myhost.com or remote3.digi.com. Use of an FQDN assumes there is a DNS server somewhere to resolve the name. For a DNS server, it does not make sense to talk about a Fully Qualified Domain Name for it, since the server itself is doing the resolving of names.

Digi’s implementation of IPv6 supports a dual stack. That is, each Digi device will have an IPv4 address and potentially several IPv6 addresses:

• Link-local address: similar to AutoIP.
• Site-local address: router-assigned.

Important Digi’s IPv6 implementation does not allow assignment of static IPv6 addresses. A Digi device gets either a link-local or site-local address.