Note: A 2022 tutorial on the many aspects of IPv6 can be found in this All Things TECH IPv6 on Mac OS article.

Enabling IPv6

In Apple macOS (all versions), OS X (all versions), and Mac OS X (versions 10.3 Panther and later), Internet Protocol version 6 (IPv6) is on by default. No action is necessary to enable IPv6. It was also supported in Mac OS X versions 10.0 Cheetah, 10.1 Puma, and 10.2 Jaguar but was turned off by default.

In addition, Apple macOS versions 12.01 and later support Internet Engineering Task Force (IETF) Request For Comments (RFC) 8925 IPv6-Only Preferred Option for DHCPv4 (option number 108), which enables IPv4-only and dual-stack nodes on a local-area network to continue to be supported while all new and updated nodes on the network are IPv6-only (sometimes referred to as IPv6-mostly access).

In the absence of applicable policy or guidance about hardening to guard against potential IPv6-related attacks, a guide for configuring Apple macOS (all versions) is provided by this article and OS X (versions 10.10 Yosemite and 10.11 El Capitan) is provided by this article.

For macOS (all versions), OS X (all versions), and Mac OS X (version 10.6 Snow Leopard), follow these instructions to manually enable IPv6.

If the following features are enabled, it is recommended that they be disabled as shown here:

1. 1. File Sharing in OS X (all versions) and Mac OS X (all versions) and
   2. AirDrop in OS X (all versions) and Mac OS X (all versions), 

Re-enabling IPv6

To re-enable IPv6 in macOS (all versions) and OS X (version 10.8 Mountain Lion and later) if it has been disabled for some reason, use the command line

networksetup -setv6automatic Wi-Fi

(and reissue the command line again for Ethernet and any other network interfaces you want to re-enable IPv6 on). Once IPv6 has been re-enabled for an interface, you can then use the System Preferences - Network panel as described in the next paragraph to manually assign its address settings.

To re-enable IPv6 in OS X (version 10.7 Lion)  and Mac OS X (all versions), open the System Preferences - Network panel. Go into the properties for each network interface and click on the Advanced - TCP/IP tab. Then click the Configure IPv6 button and set the menu to On. Click OK and then Apply Now. Close System Preferences. Note: If you want to manually assign the router's IPv6 address, choose Manually from the Configure IPv6 pop-up menu rather than just setting the menu to On. Then you can enter your system's IPv6 address and the router address and network prefix length.

If you insist on using the command line, the command to turn IPv6 on for all network interfaces is

/usr/sbin/ip6 -a

Privacy addresses were disabled by default in OS X (version 10.7 Lion) and Mac OS X (all versions). Since then they have been enabled by default in macOS (all versions) and OS X (versions 10.8 Mountain Lion and later). To disable their use with a sysctl (which must be executed each time the system is restarted):

sysctl –w net.inet6.ip6.use_tempaddr=0

while to permanently disable them, place the following in /etc/sysctl.conf

net.inet6.ip6.use_tempaddr=0

or, if that variable is already defined change its value to zero.  Next, restart the system. To temporarily re-enable their use after they have been permanently disabled, use the sysctl:

sysctl –w net.inet6.ip6.use_tempaddr=1

and to specify how often the address is recomputed (XX is in seconds), use the sysctl

sysctl -w net.inet6.ip6.temppltime=XX

To permanently re-enable them, change the value of net.inet6.ip6.use_tempaddr in /etc/sysctl.conf to 1, or place the following lines in /etc/sysctl.conf (XX is in seconds):

net.inet6.ip6.use_tempaddr=1
net.inet6.ip6.temppltime=XX

and restart the system.

The IP Transport section provides a wide variety of information for individuals and organizations interested in benefitting from the experience of others for enabling and (when necessary) disabling Internet Protocol version 6 (IPv6) in software that controls equipment receiving, transmitting, or transferring Internet Protocol (IP) packets. Such software controls layer-3 switches, routers, and computers of all sizes, from laptops, desktops, and servers up to and including supercomputers.

The following types of equipment are not included in this IP Transport section:

1. Layer-2 switches that do not process IPv6 packets (or any other IP packets), and hence are outside the scope of the IPv6 knowledge base.
2. Personal digital assistants(PDAs), also known as handheld or palmtop computers. These are largely obsolete, although smartphones (see below) that have keyboards and run recent versions of Android and/or Linux can also function as PDAs.
3. Smartphones and other mobile phones support for IPv6 is discussed in the Available IPv6 Cell Phones and Wireless Carriers article in the IPv6 and IoT Frequently Asked Questions (FAQ) section.

Enabling IPv6 in Apple macOS, OS X and Mac OS X

Enabling IPv6 in Cisco Routers and Layer-3 Switches

Enabling IPv6 in Extreme Networks Routers and Layer-3 Switches

Enabling IPv6 in Juniper Routers and Layer-3 Switches

Enabling IPv6 in Microsoft Windows 7 and earlier Versions

Enabling IPv6 in Microsoft Windows 8 and later Versions

Enabling IPv6 in Nokia Routers and Layer-3 Services Devices

Disabling IPv6 in Apple macOS, OS X and Mac OS X

Disabling IPv6 in Microsoft Windows 7 and earlier Versions

Disabling IPv6 in Microsoft Windows 8 and later Versions

IPv6 in Debian and Ubuntu Linux

IPv6 in FreeBSD Unix

IPv6 in IBM AIX, i, z/OS and z/VM

IPv6 in NetBSD Unix

IPv6 in OpenBSD Unix

IPv6 in Oracle Solaris

IPv6 in Red Hat, Mandrake, Fedora and CentOS Linux

IPv6 in openSUSE Linux and SUSE Linux Enterprise Server (SLES)

There are 5 things to consider when deploying Internet Protocol version 6 (IPv6) in the home or the SOHO:

1. An Internet Connection
2. The Computer
3. The Local Area Network (LAN)
4. Security
5. The Applications

1. An Internet Connection

The Available IPv6 Internet Service Providers (ISPs) and Networks article in the IPv6 and IoT Frequently Asked Questions (FAQ) section provides information about IPv6 connectivity offered by Internet Service Providers (ISPs).

It is easy to deploy IPv6 in the home or SOHO using a cable modem that supports the Data Over Cable Service Interface Specification (DOCSIS) 3.1 or later 4.0 or a digital subscriber line (DSL) modem that supports IPv6.

The table below lists sources of information about cable and DSL modems that support IPv6. Most modems manufactured since mid-2011 do support IPv6. Before buying a modem instead of renting or purchasing one from your ISP, verify that the modem is on your ISP’s list of approved modems. If it is not, compare the modem’s security features with the functional requirements (chapter 5) in this publication.

2. The Computer

Instructions for enabling IPv6 on many operating systems (when not already enabled by default) are available in the IP Transport section.

If IPv6 support is not available from your ISP, you can still enable IPv6 access on just your computer, rather than all the devices on your LAN, using either: 

• a tunneling mechanism such as the Hurricane Electric tunnel broker available here. It does not require any software to be installed locally but does require a stable public IPv4 address. It requires user registration. This article describes the installation process for a Fedora Linux system and this article describes the installation process for a Windows system.

or

• a Virtual Private Network (VPN). VPNs for individual use that tunnel IPv6 are listed in this article. The client software must be installed on your computer. 

3. The LAN

To enable IPv6 access for the devices on your LAN in addition to your computer takes more effort. Write-ups by individuals who have documented their home and SOHO efforts may be found in the Small Office/Home Office subtopic of the Overview of Lessons Learned Deploying IPv6 article in the General Information section.

If the networking infrastructure you aspire to deploy includes multiple computers, routers, and/or subnets, then one of the approaches offered in the IPv6 test lab setup topic of the IPv6 Test Techniques article in the IPv6 Testing section may be what you are looking for. In-depth technical recommendations and guidance for deploying your home networking infrastructure is provided by this Internet Engineering Task Force (IETF) Request For Comments (RFC) 7368 "IPv6 Home Networking Architecture Principles".

4. Security

Security concerns are just as real at home as they are at work and even more likely to receive insufficient attention. A 2025 survey of routers installed in homes or SOHOs found that 91% were running with default settings!

Here are some articles offering security tips: Keeping Your Home Network Secure, Best Practices: Consumer IoT Information & Resources (a series of 9 checklists), Best Practices for Keeping Your Home Network Secure, Home Network Security, Securing your “Internet of Things” Devices, and Smart devices: using them safely in your home.

A free Cyber Security webinar with documentation and guidance for the SOHO operator is available from the federal Cybersecurity & Infrastructure Security Agency (CISA).

Some Internet of Things (IoT) networking devices come with improved security already built-in, based on the Manufacturer Usage Description (MUD) standard.

5. The Applications

Whether you use Microsoft Edge, Mozilla Firefox, Apple Safari, Google Chrome, Opera or any other web browser, simply direct your browser to the IPv6 literal address of the website you want to view. For example,

http://ipv6.test-ipv6.com

becomes 

http://[2001:470:1:18::115].

For additional information, refer to RFC 3986 “Uniform Resource Identifier (URI):Generic Syntax".

(Caution: This substitution can sometimes fail. Explanations of possible reasons for this are available. If you encounter problems, review the Broken User FAQ article found on the above website for several possible explanations. For even more possible explanations, review this article on the ARIN IPv6 wiki.) 

Many commercial applications already support IPv6. See the IPv6 Software article in the IPv6 Deployment section for further information. Your own custom applications can also be updated to support IPv6. See the Application Conversion Introduction article in the Applications section for further information. 

This article identifies several sources of information about software products that do (or do not) support Internet Protocol version 6 (IPv6), but it does not (indeed, cannot) provide comprehensive information about the tens of thousands of products available from hundreds of vendors. There is currently no single source that identifies all software products that support IPv6.

The IPv6 support status of a software product can be determined:

1. Formally, by conducting a test based on a written, publicly available test plan, and/or
2. Informally, based on users’ experiences and developers’ statements.

When none of the sources in this article mention the IPv6 support status of a software product of interest, a search for

“software product name” ipv6 support

using any web search engine (including the double quote marks around software product name) may informally determine its IPv6 support status.

The IPv6 Product Testing Results article in the Testing section identifies four different categories of organizations:

International,
United States (US) government,
US Department of Defense, and
Commercial and open source

that have formally tested many software as well as hardware products and determined their support or lack of support.

Beginning in 2016, apps for Apple iOS 9 (or later) submitted to the App Store must first be formally tested and found to be compatible with IPv6 DNS64/NAT64 networks and also support IPv6-only networking.

(Note: The sources of IPv6 product support status mentioned below provide only informal determinations.)

Seven sections and individual articles in this IPv6 Knowledge base identify software products that do or do not support IPv6, including:

1. IP Transport section provides configuration details for various computer and router operating systems 
       that support IPv6,
2. Security section provides configuration details for various firewalls that support IPv6,
3. Applications section provides configuration details for various web browsers that support IPv6,
4. IPv6 and Virtual Private Networks (VPN) article in the Infrastructure section identifies VPNs that 
       simultaneously tunnel both IPv6 and IPv4 through a single tunnel,
5. Further Resources for Enabling IPv6 in Microsoft Windows Application Servers section of the Enabling IPv6 in
       Microsoft Windows Application Servers article in the Infrastructure section,
6. IPv6 Software Information file (last updated Dec 2011, but IPv6 support status remains valid for later  
       versions) lists software that supports IPv6 (or indicates that it does not use Internet Protocol at all):
       (a) System and Application Development Products (Libraries, Compliers, Debuggers, et cetera) and
       (b) Third Party Products (Commercial Off The Shelf [COTS], Government Off The Shelf [GOTS], 
           and Open Source).
       (Since this file was originally compiled as part of the Defense Research and Engineering (DREN)
       IPv6 Pilot, many of the entries are for software used on supercomputers.), and
7. Software-Defined Overview article in the Software-Defined Networking (SDN) knowledge base 
       mentions several specific software products. Unless otherwise specifically noted therein, those products support
       IPv6.

The Microsoft.com IPv6 Support in Microsoft Products and Services article (archived 2017, but IPv6 support status remains valid for later versions) lists many Microsoft application, server and Operating System programs that do or do not support IPv6.

The IPv6 compliance of WLCG applications file (archived 2014, but IPv6 support status remains valid for later versions) lists Worldwide Large Hadron Collider (LHC) Computing Grid (WLCG) software that supports or does not support IPv6. Since this file was originally compiled as part of the WLCG project, many of the entries are for software used on supercomputers.

The IPv6 to Standard website is maintained by the IETF IPv6 Maintenance 6man working group. It lists many, many software products that support IPv6.

Wikipedia articles indicate whether software products in several categories do or do not support IPv6, including:

common applications,
email clients,
DNS servers,
IP address management (IPAM),
mail servers,
network monitoring systems,
operating systems,
     licensed operating systems,
     open-source operating systems,
remote desktop software,
SSH clients,
SSH servers,
transition mechanisms,
Usenet newsreaders,
virtual private network services,
voice over IP (VoIP) software,
web browsers,
web hosting control panels, and
web server software. 

The University of Wisconsin Knowledgebase IPv6 Application Compatibility article listed software products that supporte IPv6 and referenced other lists of software products that supported IPv6 (archived 2009, but IPv6 support status remains valid for later versions).

The DeepSpace 6 Linux IPv6 Portal Current Status of IPv6 Support for Networking Applications article (as of 2018, but IPv6 support status remains valid for later versions) lists Networking Applications that support IPv6.