Setting the secret automatically activates this mode for all network interfaces. To make it persistent, it could be put in /etc/sysctl.d/nf or similar file: .stable_secret = 84a0:d5aa:52b0:4d35:k567:3aa6:7af5:474c This secret key must be stored in the .stable_secret sysctl. The secret key is a 128-bit hexadecimal string (shaped like an IPv6 address), which you can generate using: uuidgen | sed "s/-//g s/./:&/g s/^://" Linux kernel SLAAC supports RFC 7217 as of Linux v4.1.0 however, it must be manually activated by storing the secret seed via sysctl. To disable this feature and use traditional EUI-64 identifiers: slaac hwaddr If no prefixes match, it will still fall back to EUI-64 method.ĭhcpcd on Linux/BSD supports RFC 7217 using this option in /etc/nf: slaac private network file option, but appears to require you to explicitly list network prefixes for which this mode should be used: Systemd-networkd kind of supports RFC 7217 using this. Nmcli con modify "" ipv6.addr-gen-mode eui64 To enable or disable this feature: nmcli con modify "" ipv6.addr-gen-mode stable-privacy This feature is active by default in recent NM versions. NetworkManager on Linux supports RFC 7217 starting with NM v1.2.0, using the connection profile's UUID as part of the seed. This can also be done using netsh interface ipv6. Set-NetIPv6Protocol -RandomizeIdentifiers Disabled To enable/disable the feature: Set-NetIPv6Protocol -RandomizeIdentifiers Enabled To check if the feature is active, run a PowerShell command: Get-NetIPv6Protocol | fl RandomizeIdentifiers Windows beginning with Windows Vista uses a custom scheme, and beginning with Windows 11 uses the RFC 7217 scheme (if I remember correctly). This kind of address is still static per network – the same OS on the same machine within the same IPv6 prefix should always generate the same suffix. In some operating systems, the primary interface identifier is no longer generated from MAC or EUI-64 – instead it is generated using a hash or random seed (usually according to RFC 7217) You can use both at the same time, if you want to. RFC 7217 allows the primary, static address to be generated from an opaque hash which does not reveal any information.Īt least one but increasingly both methods are supported by popular operating systems.RFC 4941 aka "Privacy Addressing" lets outbound connections use temporary, randomly generated addresses (which are rotated every few hours).This is solved by two extensions to IPv6: Read the blog entry for more details or contribute to the blog yourself This question was a Super User Question of the Week. Note: since macOS 10.12 Sierra, according to Ars Technica Apple has adopted a new way of generating stable addresses that are not based on a MAC address, which Windows apparently had already been doing for years. For the first byte: complement the second low-order bit (the universal/local bit if the bit is a 1, make it 0, and if it is a 0, make it 1).If these bytes are not there, then there's no MAC address. Take the last 64 bits (the host identifier) and add leading zeroes: 0060:08ff:fe52:f9d8.How can I avoid my MAC addresses from being exposed?īackground: the MAC address is not in plain sight. This feels like a super cookie, and might apply to other operating systems as well. Sites such as not only show it, but even tell me it belongs to an Apple computer. On my Macs, each IPv6 address includes the MAC address of a specific computer ( not of my router).
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |