IPv6 address Flashcards
Since every device that connects to the internet is assigned an IP address, the addresses available under the IPv4 addressing standard have been exhausted. To help remedy this situation, the Internet Engineering Task Force (IETF) developed the IPv6 standard in the mid 1990’s.
facts
IPv6 address facts
-An IPv6 address is a 128-bit address made up of 8 16-bit blocks.
-Each block is separated by a colon.
-Each block is comprised of 4 hexadecimal values between 0000 and FFFF.
-Each block represents 16 bits of data (FFFF = 1111 1111 1111 1111).
-There is approximately 2128 (340 undecillion or 340 trillion trillion) available IPv6 addresses.
-The specific number of IPv6 addresses is 340,282,366,920,938,463,463,374,607,431,768,211,456
Because IPv6 addresses are so long, there are rules you can use to simplify an address. These rules are: (1/2)
Leading zeros can be omitted in each section. For example, the quartet 0284 could also be written as 284.
An address with consecutive zeros can be expressed more concisely by substituting a double colon for the group of zeros.
For example:
FEC0:0000:0000:0000:78CD:1283:F398:23AB
FEC0::78CD:1283:F398:23AB (concise form)
Because IPv6 addresses are so long, there are rules you can use to simplify an address. These rules are: (2/2)
Removing the zeros and simplifying the address is also known as address compression.
You can use address compression only once per address. For example, FEC2:0000:0000:0000:78CA:0000:0000:23AB can be abbreviated as:
FEC2::78CA:0:0:23AB
or
FEC2:0:0:0:78CA::23AB
but not
FEC2::78CA::23AB
ipv6 address facts
An IPv6 address is divided into two equal parts. The left side is the prefix and the right side is the interface ID. The prefix is comparable to the network ID in a IPv4 address and the interface ID is comparable to the host ID.
the first 64 bits of ipv6 address make up the
prefix
The prefix can be divided into various parts that identify things such as geographic region, the ISP, the network, and the subnet.
facts
The first 48-bits of the address define the site prefix. The site prefix defines the location of the address and is assigned by the local ISP.
facts
The next 16-bits make up the subnet ID. This defines the network the device is connected to.
facts
this notation can be used to indicate the prefix-length. As with an IPv4 address, this shows which portion of the address used for the prefix
CIDR
Because addresses can be allocated based on physical location, the prefix generally identifies the location of the host. The prefix is often referred to as the global routing prefix.
facts
The last 64-bits in the address is the
interface ID
This is a unique identifier for each device, similar to a MAC address
facts
Addresses are assigned to interfaces (network connections), not to the host. Technically, the interface ID is not a host address, but is often referred to as the host address.
facts
must be unique within a subnet, but the same interface ID can exist on multiple subnets.
Interface IDs
Extended Unique Identifier 64 (EUI-64) format
ensure that the interface ID is unique for every host on the network
which format does ipv6 use?
Extended Unique Identifier 64 (EUI-64) format