An IPv6 (Normal) address has the following format: y: y: y: y: y: y: y: y where y is called a segment and can be any hexadecimal value between 0 and FFFF. The segments are separated by colons - not periods. An IPv6 normal address must have eight segments, however a short form notation can be used in the Tape Library Specialist Web interface for segments that are zero, or those that have. Feb 11, 2011 On my Macs, each IPv6 address includes the MAC address of a specific computer (not of my router). Sites such as ipv6-test.com not only show it, but even tell me it belongs to an Apple computer. This feels like a super cookie, and might apply to other operating systems as well. How can I avoid my MAC addresses from being exposed? As you can see, the 'sh arp' or 'sh ip arp' commands also give you the MAC addresses, so essentially the 'sh mac add' is only to get the port in which the device is connected. It helps to Ping the subnet's broadcast address (e.g. '10.1.1.255') to load the ARP table.
While MAC addresses are 48 bits, that is a lot more than the 32 bit IPv4 adresses (even counting the reserved addresses 255, 127, Class D Multicast etc ), will we not eventually run out of them? Also, IPv6 addresses may be derived from the 48 bit MAC addresses. And IPv6 address space is much larger than the MAC address space. NetLookup is a searchengine aimed towards computer networking professionals. Search for MAC addresses vendors, IP-addresses, ASN and more.
Both MAC Address and IP Address are used to uniquely defines a device on the internet. NIC Card's Manufacturer provides the MAC Address, on the other hand Internet Service Provider provides IP Address.
The main difference between MAC and IP address is that, MAC Address is used to ensure the physical address of computer. It uniquely identifies the devices on a network. While IP address are used to uniquely identifies the connection of network with that device take part in a network. How to enhance a photo on mac.
Let's see the difference between MAC Address and IP Address:
| S.NO | MAC Address | IP Address |
|---|---|---|
| 1. | MAC Address stands for Media Access Control Address. | IP Address stands for Internet Protocol Address. |
| 2. | MAC Address is a six byte hexadecimal address. | IP Address is either four byte (IPv4) or six byte (IPv6) address. |
| 3. | A device attached with MAC Address can retrieve by ARP protocol. | A device attached with IP Address can retrieve by RARP protocol. |
| 4. | NIC Card's Manufacturer provides the MAC Address. | Internet Service Provider provides IP Address. |
| 5. | MAC Address is used to ensure the physical address of computer. | IP Address is the logical address of the computer. |
| 6. | MAC Address operates in the data link layer. | IP Address operates in the network layer. |
| 7. | MAC Address helps in simply identifying the device. | IP Address identifies the connection of the device on the network. |
| 8. | MAC Address of computer cannot be changed with time and environment. | IP Address modifies with the time and environment. |
| 9. | MAC Address can't be found easily by third party. | IP Address can be found by third party. |
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- IPv6 Tutorial
- IPv6 Useful Resources
- Selected Reading
Hexadecimal Number System
Before introducing IPv6 Address format, we shall look into Hexadecimal Number System. Hexadecimal is a positional number system that uses radix (base) of 16. To represent the values in readable format, this system uses 0-9 symbols to represent values from zero to nine and A-F to represent values from ten to fifteen. Every digit in Hexadecimal can represent values from 0 to 15.
[Image: Conversion Table]Address Structure
An IPv6 address is made of 128 bits divided into eight 16-bits blocks. Each block is then converted into 4-digit Hexadecimal numbers separated by colon symbols.
For example, given below is a 128 bit IPv6 address represented in binary format and divided into eight 16-bits blocks: Directv now for mac.
0010000000000001 0000000000000000 0011001000111000 1101111111100001 0000000001100011 0000000000000000 0000000000000000 1111111011111011
Each block is then converted into Hexadecimal and separated by ‘:' symbol:
2001:0000:3238:DFE1:0063:0000:0000:FEFB
Even after converting into Hexadecimal format, IPv6 address remains long. IPv6 provides some rules to shorten the address. The rules are as follows:
Rule.1: Discard leading Zero(es):
In Block 5, 0063, the leading two 0s can be omitted, such as (5th block):
2001:0000:3238:DFE1:63:0000:0000:FEFB
Rule.2: If two of more blocks contain consecutive zeroes, omit them all and replace with double colon sign ::, such as (6th and 7th block):
2001:0000:3238:DFE1:63::FEFB
Consecutive blocks of zeroes can be replaced only once by :: so if there are still blocks of zeroes in the address, they can be shrunk down to a single zero, such as (2nd block):
2001:0:3238:DFE1:63::FEFB
Interface ID
IPv6 has three different types of Unicast Address scheme. The second half of the address (last 64 bits) is always used for Interface ID. The MAC address of a system is composed of 48-bits and represented in Hexadecimal. MAC addresses are considered to be uniquely assigned worldwide. Interface ID takes advantage of this uniqueness of MAC addresses. A host can auto-configure its Interface ID by using IEEE's Extended Unique Identifier (EUI-64) format. First, a host divides its own MAC address into two 24-bits halves. Then 16-bit Hex value 0xFFFE is sandwiched into those two halves of MAC address, resulting in EUI-64 Interface ID.
[Image: EUI-64 Interface ID]Conversion of EUI-64 ID into IPv6 Interface Identifier
To convert EUI-64 ID into IPv6 Interface Identifier, the most significant 7th bit of EUI-64 ID is complemented. For example:
[Image: IPV6 Interface ID]Global Unicast Address
Find Mac Address In Ipv6 Address
This address type is equivalent to IPv4's public address. Global Unicast addresses in IPv6 are globally identifiable and uniquely addressable.
[Image: Global Unicast Address]Mac Address Vs Ipv6
Global Routing Prefix: The most significant 48-bits are designated as Global Routing Prefix which is assigned to specific autonomous system. The three most significant bits of Global Routing Prefix is always set to 001.
Link-Local Address
Auto-configured IPv6 address is known as Link-Local address. This address always starts with FE80. The first 16 bits of link-local address is always set to 1111 1110 1000 0000 (FE80). The next 48-bits are set to 0, thus:
[Image: Link-Local Address]Link-local addresses are used for communication among IPv6 hosts on a link (broadcast segment) only. These addresses are not routable, so a Router never forwards these addresses outside the link.
Unique-Local Address
This type of IPv6 address is globally unique, but it should be used in local communication. The second half of this address contain Interface ID and the first half is divided among Prefix, Local Bit, Global ID and Subnet ID.
[Image: Unique-Local Address]Prefix is always set to 1111 110. L bit, is set to 1 if the address is locally assigned. So far, the meaning of L bit to 0 is not defined.Therefore, Unique Local IPv6 address always starts with ‘FD'.
Scope of IPv6 Unicast Addresses:
[Image: IPv6 Unicast Address Scope]The scope of Link-local address is limited to the segment. Unique Local Address are locally global, but are not routed over the Internet, limiting their scope to an organization's boundary. Global Unicast addresses are globally unique and recognizable. They shall make the essence of Internet v2 addressing.
