#Convert mac address into ipv6 eui 64 64 bits
Similar to an IPv4 subnet number, there are a maximum of 64 bits for both the global routing prefix and subnet ID. Subnet ID: is used by organizations to construct a local network (site). Currently, the first 3 bits of every assigned global routing prefix is 001. A global routing prefix is comprised of at least 48 bits. Global routing prefix: is assigned by a service provider to an organization. These components are described as follows: IPv6 global unicast addresses support route prefix summarization, helping limit the number of global routing entries.įigure 7-2 shows a global unicast address consisting of a global routing prefix, subnet ID, and interface ID. The loopback address cannot be used as the source or destination IP address of packets needing to be forwarded.Īn IPv6 global unicast address is an IPv6 address with a global unicast prefix, which is similar to an IPv4 public address. This IPv6 loopback address is usually used as the IP address of a virtual interface, such as a loopback interface. Similar to the IPv4 loopback address 127.0.0.1, the IPv6 loopback address is used when a node needs to send IPv6 packets to itself. Devices do not forward packets with an unspecified address as the source IP address. It can be used as the source IP address of some packets, such as Neighbor Solicitation (NS) messages, in duplicate address detection. The IPv6 unspecified address is 0:0:0:0:0:0:0:0/128 or ::/128, indicating that an interface or a node does not have an IP address. IPv6 defines multiple types of unicast addresses, including the unspecified address, loopback address, global unicast address, link-local address, and unique local address. However, this rule does not apply to an IPv6 address with a 127-bit network prefix. Packets sent to an IPv6 unicast address are delivered to the interface identified by that address.Ī global unicast address cannot be the same as its network prefix because an IPv6 address which is the same as its network prefix is a subnet-router anycast address reserved for a device. Since each interface belongs to a node, the IPv6 unicast address of any interface can identify the relevant node. Instead, a multicast address can be used as a broadcast address.Īn IPv6 unicast address identifies an interface. Unlike IPv4, there is no broadcast IPv6 address. IPv6 addresses can be classified as unicast, multicast, or a new class called anycast.
#Convert mac address into ipv6 eui 64 mac
Taking the insertion of a hexadecimal number FFFE (1111 1111 1111 1110) into the middle of a MAC address as an example, see Figure 7-1 for the detailed conversion procedure. For Eth-Trunk interfaces and its sub-interfaces and VLANIF interfaces, the EUI-64 address is generated based on the MAC address of an interface, with FFFE added in the middle.For loopback interfaces, VBDIF interfaces, and tunnel interfaces, the EUI-64 address is generated based on the MAC address of an interface, with the last two bytes following the interface index added in the middle.To address stacking conflicts, the EUI-64 address of a Layer 3 physical interface or a Layer 3 sub-interface is generated based on the MAC address of the physical interface, with the last two bytes following the interface index added in the middle. Different Layer 3 physical interfaces may have the same MAC address.If the interface has not been configured with a MAC address, the EUI-64 address is generated based on the following rules: If the interface has been configured with a MAC address, the EUI-64 address is generated based on the MAC address of the interface, with FFFE added in the middle. The 64-bit IPv6 interface ID is translated from a 48-bit MAC address by inserting a hexadecimal number into the MAC address, and then setting the U/L bit (the leftmost seventh bit) to 1. This address is derived from the link-layer address (such as a MAC address) of the interface. The 64-bit interface ID in an IPv6 address identifies a unique interface on a link. Generating an interface ID in EUI-64 format is the most common practice. You can manually configure the interface ID, generate it through system software, or generate it in IEEE 64-bit Extended Unique Identifier (EUI-64) format. Interface identifier (interface ID): Corresponds to the host ID of an IPv4 address. Network prefix: Corresponds to the network ID of an IPv4 address.