IpV6 on the Inside of Packetshaper.


Article ID: 166626


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My Packetshaper is discovering IPV6 addresses when there are no IPV6 configure devices on my network.


The Packetshaper will discover and create a IPV6 class when it sees any traffic coming from a IPv6 configured devices, however if there are no devices configured with IPV6 why does the Packetshaper reports and created a class for IPv6.

It is normal to the Packetshaper reporting IPV6 if there are devices on the network are advertising link local address.


The Following explanation is referred from the following Microsoft KB 


The link-local address is a combination of the link local prefix FE80::/64 and a 64-bit IPv6 interface identifier (ID).

In Windows XP and Windows Server 2003, the IPv6 interface ID is derived from the Extended Unique Identifier (EUI)-64 address. The EUI-64 address is either assigned to a network adapter or derived from the 48-bit media access control (MAC) address of a network adapter. To create the EUI-64 address from the 48-bit (6-byte) Ethernet MAC address, the hex digits 0xff-fe are inserted between the third and fourth bytes of the Ethernet MAC address.

For example, for the MAC address 00-60-08-52-f9-d8, the hex digits 0xff-fe are inserted between 0x08 (the third byte) and 0x52 (the fourth byte) of the MAC address, forming the EUI-64 address 00-60-08-ff-fe-52-f9-d8.

To obtain an IPv6 interface identifier from an EUI-64 address, the Universal/Local bit, the second low-order bit of the first byte of the EUI-64 address, is complemented (if it is a 1, it is turned to 0, and if it is a 0, it is turned to 1). For example, for the EUI-64 address of 00-60-08-ff-fe-52-f9-d8, the second low-order bit of 0x00 is 0, which, when complemented, becomes a 1. The result is that for the first byte, 0x00 becomes 0x02. Therefore, the IPv6 interface identifier corresponding to the EUI-64 address of 00-60-08-ff-fe-52-f9-d8 (corresponding to the Ethernet media access control address of 00-60-08-52-f9-d8) is 02-60-08-ff-fe-52-f9-d8.

Because the link-local address is the combination of the prefix FE80::/64 and the 64-bit interface identifier expressed in IPv6 colon-hexadecimal notation, the link-local address of this example node, with the prefix FE80::/64 and the interface identifier 02-60-08-ff-fe-52-f9-d8, is fe80::260:8ff:fe52:f9d8.

In Windows Vista and Windows Server 2008, the interface ID by default is randomly derived, rather than based on the EUI-64 address. You can disable random interface IDs with the netsh interface ipv6 set global randomizeidentifiers=disabled command or enable random interface IDs with the netsh interface ipv6 set global randomizeidentifiers=enabled command