Ch29-IPv6 Addressing and Subnetting Flashcards
A type of unicast IPv6 address that has been allocated from an range of public, globally-unique IP addresses, as registered through IANA/ICANN, its member agencies, and other registries or ISPs
global unicast address
An IPv6 prefix that defines an IPv6 address block made up of global unicast addresses, assigned to one organization, so that the organization has a block of globally unique IPv6 addresses to use in its network
global routing prefix
A type of IPv6 unicast address meant as a replacement for private IPv4 IP addresses
unique local address
The number that represents the ipv6 subnet, also known as the IPv6 prefix, or, more formally, the subnet router any cast address
subnet ID (or prefix ID)
A special anycast address in each IPv6 subnet, reserved for use by routers as a way to send a packet to any router on the subnet. The address’s value in each subnet is the same as the subnet ID
subnet router anycast address
Describe the EUI-64 process
The eui-64 process is a method used to derive unique interface ID for global unicast, unique local, and link-local IPv6 address. The process requires: 1. Splitting the MAC address at the 24th bit boundary 2. Inserting hex FFFE 3. Inverting the 7th bit of the MAC address The resulting 64 bit value is added to the provided prefix, resulting in a complete IPv6 address
An IPv6 address is configured on a working interface. What functions does a router enable once this occurs?
- Gives the interface a unicast IPv6 address 2. Enables routing of packets in/out of that interface 3. Defines the subnet that now exists off that interface 4. Adds connected IPv6 route to the routing table
What is the forwarding scope of a link-local IPv6 address.
Forwarding scope is link-local only; routers will not route packets destined to a link-local address to other links.
Are link-local addresses classified as unicast or multicast?
unicast
Link-local addresses might be automatically generated by a host; what function does this serve?
Solves some initialization problems before the host has global unicast address
By definition, the first 10 bits of link-local addresses match FE80::/10 — what possible values could be expected for a link-local prefix?
Prefixes beginning with: FE8 FE9 FEA FEB
The prefix of an IPv6 link-local address will be FE80::/10, with the next 54 bits expressed as binary 0. How is the interface ID of a link-local addresses derived?
It may be manually configured or automatically generated, including by EUI-64
What are common uses for link-local addresses?
- overhead protocols within the subnet 2. next-hop address for IPv6 routers
When does Cisco IOS create a link-local address for an interface?
Any time an interface has an IPv6 unicast address configured on it
The fist hex digits of a given IPv6 address are 2 or 3; what type of address does this imply?
global unicast