Why Does My Wifi Have 2 Ipv6 Addresses

The emergence of the next generation Internet Protocol (IP) – IPv6, introduced an abundance of addresses to replace its predecessor, IPv4. It was introduced due to an increase in internet-enabled devices demanding more IP addresses than IPV4 could provide. The IPv6 protocol uniquely identifies devices over the internet or a local network, similar to how a telephone number is needed to dial a specific person.

A wifi-connected device displaying two different IPv6 addresses doesn’t indicate a problem but reflects two essential techniques applied by IPv6 – the Stateless Address Autoconfiguration (SLAAC) and Privacy Extensions.

With SLAAC, every device on a network creates its own IPv6 address using a combination of locally available information and certain details advertised by routers. A part of this process includes generating a link-local address which is used specifically for internal network communication and typically begins with “fe80::”.

On the other hand, to obscure the device’s identity and increase user privacy, routers supporting IPv6 may use Privacy Extensions as defined in RFC 4941. This means your device will periodically generate new, random IPv6 addresses from the prefix provided by your ISP.

This makes it harder to track the online activities associated with your device as its publicly visible IP keeps changing over time. As a result of these practices, your device can have multiple active IPv6 addresses at any given time.

In some cases, if you’re running a dual stack, your wifi might support both the IPv4 and IPv6 protocols. If that’s true, one of your IPv6 addresses will be there along with an IPv4 address.

ipconfig /all

While this may seem a bit complicated, these dual addresses actually give you the best flexibility and functionality in our transitioning digital landscape.
IPv6, or Internet Protocol version 6, is used to assign addresses to devices on a wifi network. It’s a fascinating topic with many sides to explore. In particular, one puzzling question that may arise as you delve deeper into the complex world of IP networking is: Why does my wifi have two IPv6 addresses?

To unravel this quandary, let’s start by understanding the 2 core types of IPv6 addresses: global and link-local addresses.

## Global Unicast Address (GUA)

<'code'>
2001:0db8:85a3:0000:0000:8a2e:0370:7334

A unique global address usable anywhere on the internet, defined in the general format above. This would be similar to the public IPv4 address you might have been assigned by your internet service provider (ISP).

## Link-Local Addresses (LLA)
<'code'>
fe80::200:5aee:feae:9b86

This type of address is only significant and usable over a particular network segment or “link”. Think of it as the house number where your device lives on your local street (the wireless network).

With that foundational knowledge established, the reason your wifi connection has two IPv6 addresses can now be laid bare: your network interface is automatically generating both a link-local address for local connectivity and potentially receiving a global unicast address from a router for wider internet communication.

Ellaborating on these aspects:

## Autoconfiguration and Decentralization

Thanks to a capability called autoconfiguration, your network devices can use link-local addresses to communicate without requiring a central authority like a Dynamic Host Configuration Protocol (DHCP) server. Your device creates its link-local address based on the MAC address of the network card, which is why you see an address beginning with ‘fe80’.

This feature significantly simplifies networking, reduces dependency on central servers, and allows devices to connect directly to each other within the same network segment.

## Global Communication

On the other hand, Global Unicast Addresses are usually provided to your devices through a router via DHCPv6 or another autoconfiguration protocol. This address is what your devices use to communicate across the internet, making possible all online activities.

## Stability and Privacy

Another possible reason you could be seeing more than one IPv6 address is the use of temporary addresses for privacy. As part of IPv6, it’s standard to generate random, temporary global addresses that change periodically. By rotating addresses, it makes it harder to track a specific device online, thereby enhancing user privacy.

In summary, multiple IPv6 addresses on your wifi device are quite normal. They serve various functions such as facilitating local network communication, enabling internet access, and providing enhanced privacy. Such decentralization of network operations gives way to greater adaptability and scalability, especially critical in environments with large numbers of interconnected devices, typical with IoT (Internet of Things) deployments. [Refer](https://www.internetsociety.org/resources/doc/2011/internet-protocol-version-6-ipv6-understanding-why-it-matters/)++

For more details on the real depths of IPv6 addressing including special addresses, subnetting or how applications choose which address to use, there’s comprehensive documentation available on the [official Internet Engineering Task Force (IETF)](https://tools.ietf.org/html/rfc4291) website.
When examining Wi-Fi networks and their Internet Protocol (IPv6) addresses, you might get intrigued to discover that your connection appears to flaunt two distinct IPv6 addresses. This peculiarity may seem perplexing at first glance but delves into the fundamental design of IPv6, making multiple IPs not just common but functional.

To better understand this concept, we first need to decode the elements that constitute IPv6 addressing:

• Interface Identifier: The Interface Identifier uniquely identifies each interface on a specific network. Each machine connecting to a network has its unique identifier.

• Global Unicast Addresses: As the primary type of IPv6 address, it identifies a single interface in an IPv6-enabled network.

• Link Local Address: This is used exclusively for communication within the local subnet.

Remember that a single device can bear multiple IPv6 addresses. Your router could assign several different scope addresses to your device over your Wi-Fi connection like a Global Static IP or Temporary IP which routinely changes based on the privacy extension mentioned in RFC 4941 [1]. This setup enhances privacy by making it exceedingly challenging to track a device through its changing IPs.

The process of assigning multiple IP addresses to a host involves a few steps:

– The router sends a signal named a multicast Router Advertisement (RA).
– The device’s network interface card (NIC) tweaks this signal to create a Global and Link Local IPv6 address.

Here’s a relevant piece of Python code showcasing how IPv6 addresses can be handled:

import socket
info = socket.getaddrinfo("localhost", None)

ipv6_addr_list = [ i for i in info if i[0] == socket.AF_INET6 ]
print(ipv6_addr_list)

This particular Python script fetches the localhost’s IP address details, segregates the IPv6 entries and prints them on the console.

In communicating over a network, the choice between these IP types depends on the destination. For instance, when one communicates with devices within the same network segment, link-local addresses are leveraged. However, for communicating over the internet, Global Unicast Addresses are employed.

Devices usually appear to sport two IPv6 addresses due to the simultaneous functioning of Global and Link Local Addresses. To sum up, having multiple IPv6 addresses affiliated with your Wi-Fi doesn’t signify an anomaly but rather reflects a seamless operational strategy underlining the flexible architecture of IPv6.In the realm of Internet Protocol version 6 (IPv6), the Dynamic Host Configuration Protocol for IPv6 (DHCPv6) plays a central role in assigning multiple IP addresses to devices on your network. This knowledge might help you make sense of why your Wifi displays two IPv6 addresses.

Making use of DHCPv6, each device gets assigned both a global and local IPv6 address. This is the primary reason why your WiFi likely shows two IPv6 addresses. To elaborate:

-----
Local Address.
-----
Network: 192.168.1.0/24
Host: 192.168.1.1

A global address is just as the title suggests, ‘global’, meaning it’s unique throughout the entire internet. Your ISP provides this address to you. It’s what your computer uses to interface with other networks or devices residing outside of your local network.

-----
Global Address.
-----
Network: 2000::/3
Host: 2001:db8:85a3:8d3:1319:8a2e:370:7348

On the contrary, a local address caters to different needs. Sometimes also referred to as a link-local address, it is specific to your internal network. The computer utilizes this address to communicate with other devices on the same network.

The addition of a local address to your system is not only facilitated through DHCPv6 but is also influenced by other factors like the IPv6 privacy extensions and Stateless Address Autoconfiguration (SLAAC).

SCENARIO TABLE:

To view your IPv6 addresses:

To confirm the existence of these multiple addresses, simply open up the command prompt or terminal on your device and type in

ipconfig (Windows)

or

ifconfig (Mac/Linux)

. You will see lines displaying both global and link-local IPv6 addresses under your current Wifi network.

Remember that the distinctive feature of IPv6 is its considerable address space. Henceforth, assigning multiple addresses to a single network interface finds its share of advantages in terms of network connectivity, privacy, and security management. Spend some time getting to know IPv6 – it won’t be long before IPv4 fades into history!

For further understanding, you can learn more about DHCPv6 here and IPv6 addressing schemes here.The presence of dual IPv6 addresses on your WiFi network can be driven by several factors. These major influencing elements support the operational efficiency, security, and flexibility of the connected devices in the network environment.

• IPv6 Stateless Address Autoconfiguration (SLAAC): One of the most influential factors driving this phenomenon is SLAAC [1]. SLAAC, specified in RFC 4862, is a core part of the IPv6 protocol suite that allows a node to automatically configure an IP address without the need for a DHCP server.

   ip -6 addr show wlan0

Running the above command line will show you something like the below output:

    inet6 2001:db8:1:0:f816:3eff:fef6:2e74/64 scope global mngtmpaddr dynamic 
    valid_lft 2591965sec preferred_lft 604765sec
    inet6 fe80::f816:3eff:fef6:2e74/64 scope link 
    valid_lft forever preferred_lft forever

The second IPv6 line that starts with ‘fe80’ is automatically generated. This so called ‘unique local address’ (ULA) is an IPv6 version of the link-local address that previous IPv4 implementations created using Automatic Private IP Addressing (APIPA).

• RFC 4941 Privacy Extensions: Yet another reason you could be observing two (or even more) IPv6 addresses on your devices is due to the implementation of RFC 4941 Privacy Extensions [2]. To enhance user privacy, these extensions allow the creation of temporary, anonymous internet addresses which bear no relationship to the MAC address of the device. For example, your wifi-enabled laptop or smartphone will commonly use these short-lived, randomised addresses when connecting to external websites or services. Hence, it’s possible to have both a stable, auto-configured IPv6 address (likely based on the device’s MAC address) and one or more privacy-enhanced IPv6 addresses simultaneously.

With these factors at play, don’t be surprised if your WiFi devices are showing more than one IPv6 address. It’s perfectly normal and signifies that your network environment is flexible enough to accommodate various scenarios and demands.

Every device on a network has an IP address, which is used to identify it. Traditionally, these were IPv4 addresses, but due to the exponential growth of the internet and the exhaustion of available IPv4 addresses, a new version, IPv6, was developed. Normally, your WiFi router lets your device obtain multiple IPv6 addresses for functionality purposes.

These are primarily two types:

• Global Unicast Address
• Link Local Address

1. Global Unicast Address

The Global Unicast Address in IPv6 is equivalent to the public IPv4 address. This is a globally unique identifier that can be routed directly on the internet. These addresses typically start with a ‘2’ or ‘3’.

    Example: 2001:0db8::/32

Your WiFi connected device(s) are allocated one or many global unicast addresses depending upon the needs of various applications residing on the device on an “as per need” basis. The main “functional difference” from an end user perspective between both the addresses would be if an application/service running on your WiFi device needs “Communicating with the outside world,” it will likely use the Global Unicast Address.

2. Link Local Address

Lastly, there’s another type of IPv6 Address called the Link-Local Address that wouldn’t necessarily tie up to “Why Does My Wifi Have 2 Ipv6 Addresses” but definitely contributes to the multiple IPv6 address part. To understand this, we need to first grasp the concept of link-local addresses (NetworkLessons.com).

    Example: fe80::/10

They are automatically configured on every network adapter and they are not routable over the internet. They exist to allow connectivity before full IPv6 connectivity is set up and only ever exist within a single network segment.

So for example, if your device is communicating with another device on the same local network (perhaps transferring files across a local network), that communication may well use the LINK-LOCAL address.

In summary, your device having multiple IPv6 addresses provides flexibility for applications and services running on your device. Depending on whether those services need to communicate locally or across the wider internet, they can choose to use either the global unicast or the link-local address. This is why your WiFi has 2 IPv6 addresses and their functional differences.

Privacy Extensions for IPv6 present an insightful mechanism for enhancing your online security and privacy. This feature, enabled by default in many operating systems, works by creating a temporary, random Interface Identifier (IID) for non-static network connections, commonly known as dynamic networks.

You might be wondering now: Why does my Wifi have 2 IPv6 addresses? The answer lies deeply embedded in this function of Privacy Extensions.

IPv6 uses a 128-bit address. The first 64 bits define the network prefix, while the remaining 64 serve as the Interface Identifier (IID), which signifies a specific device on that network. Without privacy extensions, IIDs are primarily obtained using the MAC, a unique hardware identifier of the network interface. Unfortunately, this leaves your device prone to tracking or targeted attacks since your MAC can provide an unwelcome beacon pointing directly to your device each time it connects to a new network.

Enter Privacy Extensions. Instead of merely exposing the static MAC-derived IID, your device generates a random IID for its public-facing connection, changing at regular intervals. This gives you two different types of IPv6 addresses:

• The first is your Primary IPv6 Address (also termed “stable” or “permanent”). It doesn’t change unless you alter your device’s network settings. Its IID portion derives from your device’s MAC.

• The other one is the Temporary IPv6 Address, generated using the privacy extension. This address changes over time, offering improved privacy by making your online activities harder to track. Your device might actually have multiple temporary IPv6 addresses if previous ones haven’t expired yet.

So, when you look at your device’s IPv6 addresses, you’re likely seeing both its primary and one (or more) temporary addresses, recalling our original question – why does my Wifi have 2 IPv6 addresses.

This dual-address approach provides an excellent compromise between continual network functionality (e.g., retaining stable connections for prolonged sessions) and privacy-enhancement (preventing individual devices from being readily identifiable across diverse networks).

In Python for instance, this would involve getting all the available IPv6 addresses:

import socket

addresses = socket.getaddrinfo(socket.gethostname(), None, socket.AF_INET6)

for address in addresses:
    print(address[4][0])

If Privacy Extensions are enabled, the list will certainly include both permanent and temporary addresses, indicating that your system has indeed employed this crucial privacy-ensuring function.

For extended reading, check out the RFC 4941: Privacy Extensions for Stateless Address Autoconfiguration in IPv6.It’s not atypical for your WiFi-enabled device to possess two IPv6 addresses. Understanding the rationale behind this starts with a comprehension of IPv6 (Internet Protocol version 6). Considerably enhanced over its predecessor, IPv4, this communication protocol is designed for the internet to identify and locate systems globally [source].

The rationale for two IPv6 addresses lies in the design of the Internet Protocol itself. Intuitively, the idea of having multiple addresses may seem peculiar, but it is highly practical. Here are primary reasons:

• Global Unicast Address (GUA). This type of IPv6 address is globally routable and typically applied to connect to external networks. It’s like your public phone number that others can use to reach you internationally.

Example GUA: 2001:0db8:85a3:0000:0000:8a2e:0370:7334

• Link-Local Address (LLA): This type of address ordinarily serves for network operations within the same “link” or subnet, and by default, every IPv6-ready device generates and assigns an LLA to its interface autonomously irrespective of the presence of a router. LLA usually begins with “fe80”.

Example LLA: fe80::1ff:fe23:4567:890a

They serve different purposes:

• Adaptable Communication: With dual IP settings, a single device can interact with both local and international applications concurrently without any disruption.
• Inherited Versatility: LLAs exist even in the absence of configured network services, making them useful for setting up networking services or troubleshooting. On the other hand, GUAs enable interaction on a broader scale.
• Enhanced Security: Given that LLAs restrict their environment to a local subnet, this isolation minimizes potential security threats to some extent.

However simplistic this dual-addressing feature might be, it has been instrumental to the operational success of contemporary networking technologies such as stateless address autoconfiguration (SLAAC) and Neighbor Discovery Protocol (NDP) which lie at the IPv6’s core value proposition [source].

Imbibing the concept of SLAAC, for instance, imbues us with the understanding of how these IPv6 addresses get auto-generated once connected to a network. With a prefix advertised by routers in the network, a device combines this prefix with a so-called Interface Identifier formed from the MAC address to create the IPv6 address.

Lastly, let me showcase simplified Python code that utilizes socket library to fetch all IPv6 addresses attached to certain network interfaces:

import socket
import netifaces

addresses_ipv6 = []
for interface in netifaces.interfaces():
    try:
        addrs = netifaces.ifaddresses(interface)[netifaces.AF_INET6]
    except KeyError: 
        continue
    for addr in addrs:
        if 'addr' in addr:
            addresses_ipv6.append(addr['addr'])

print(addresses_ipv6)

Arguably, the richness of IPv6’s addressing plan, featuring this duality, has made it stand out against IPv4, condoning its widespread adoption today.

Bear in mind that IT practices are primarily solving problems by design while optimizing efficiency. Therefore, the arrangement of having two IPv6 addresses, though seemingly odd, reflects how innovations have evolved to meet the computing demands of our rapidly unfolding digital world.Sure, let’s delve into the core of the subject matter: Double IPv6 addresses on a Wi-Fi network resultant from Router Advertisements.

See also

NetworkingProtocol

·June 9, 2023·33 min read

Is Ethernet Ip Udp Or Tcp

IPv6 addresses are designed to be automatically configured. Your device can configure its own IP address without needing a DHCP server, differing from IPv4 configurations that typically rely on DHCP. This is colloquially known as Stateless Address Autoconfiguration (SLAAC), which makes use of Router Advertisement (RA) messages to assign addresses RFC2462.

To understand why your Wi-Fi shows two IPv6 addresses, it’s important we comprehend how this autoconfiguration process works at various stages:

– When your device connects to a network, it generates a link-local IP address (which always starts with ‘fe80::’). This is used for internal network communication.

– Next, your device listens for any RA messages broadcasted by routers. The device then utilizes the prefix in these RA messages and appends its interface identifier (usually based on the MAC address) to create a global unicast IPv6 address.

– Additionally, Privacy Extensions for SLAAC may generate temporary addresses to provide traffic anonymity over the internet. These are termed ‘privacy addresses’ or ‘temporary addresses,’ designated for external connections RFC4941.

Here is a simple representation of potential IPv6 addresses you could observe on a device: