IPv6 Flashcards
IPv6 addressed are made up of ___ hexadecimal numbers and organized into __ quartets.
32, 8
Each quartet is separated by a ___.
Colon
Each quartet is represented as a hexadecimal number between __ - __ and __ - __.
1-9, A-F (A being 10, B being 11, and so on…)
How many sets of consecutive zeros can be substituted by a double colon ::?
Only 1
Unicast addresses include…
Link local, unique local, and global unicast
Link local addresses are…
Only valid on the current subnet (not globally routable)
Unique local addresses are…
Private addresses used for communication within a site or between a limited number of sites. Does not cross a public network.
Unique local prefixes include…
FE80:://10, FE8, FE9, FEA, FEB
Link local addresses are used for…
Automatic address configuration (similar to APIPA), neighbor discovery
Unique local addresses are…
Private addresses used for communication within a site or between a limited number of sites. Does not cross public network.
Unique local prefixes include…
FC00::/7, FD
Global unicast addresses are…
Addresses that are assigned to individual interfaces that are globally unique (throughout the entire internet)
Global unicast prefixes include…
Anything that is not link-local, unique local, or multicast
What is the RIR of an IPv6 Address?
The regional internet registry, often by continent. In a /64 environment the RIR is the first 12 bits or /12 of an address.
What does NIR stand for?
National internet registry
What does LIR stand for?
Local internet registry
What does ISP stand for?
Internet service provider
What is the NIR/LIR/ISP of an IPv6 address?
The regional organization subdivides its block of IP addresses into small blocks and assigns those blocks to NIR, LIR, or ISP. It can vary, but the minimum prefix length is 32 bits or /32.
What is the site of an IPv6 address?
The site is a block of IP addresses requested by individual companies/organizations from an NIR/LIR/ISP to use in private networks. By convention, each site is assigned a 48-bit site ID or /48
What is the subnet of an IPv6 address?
The remaining 16 bits in the global routing prefix are used by the local network admin to creating subnets.
What is the interface ID of an IPv6 address?
The host ID, anything after the subnet ID
What is the global routing prefix?
The first three octets (RIR and site)
Multicast addresses are…
A dynamic group of hosts. Packets sent to a multicast address are sent to all interfaces identified by that address.
All multicast addresses have a…prefix.
FF00::/8
Local link multicast prefix
FF02::/16
Single node-restricted multicast prefix
FF01::/16
All nodes on the local link prefix
FF02::1
All interfaces on a node prefix
FF01::1
All routers on the local link prefix
FF01::2
All DHCP servers or DHCP relay agents on local-link prefix
FF02::1:2
What is an anycast address?
A unicast address that is assigned to more than one interface. Can be link-local, unique local, or global unicast. Can be used to locate nearest DNS or network time server.
What is the loop back address for the local host?
0:0:0:0:0:0:0:0:1 or ::1 or ::1/128
What is an unspecified address?
0:0:0:0:0:0:0:0 or :: or ::/128
Used when there is no IPv6 configuration (usually during startup)
What is EUI-64?
The Extended Unique Identifier can be used to auto generate the host portion of an endpoint IP address. Used by DHCP. Involves several steps.
What are the steps of EUI-64?
- Break MAC address into two halves
- Put FFEE between two halves
- Convert 7th bit into 1 and then calculate hexadecimal value of first 8 bits
- Voila
What is dual stack configuration?
When both IPv4 and IPv6 protocol stacks run concurrently on a device. The device will use IPv4 to communicate with IPv4 devices and vice versa for IPv6.
What is tunneling?
When one protocol is wrapped in another to enable transmission across limited networks. Example: IPv4 packet wrapped with IPv6 packet to enable traffic to traverse IPv6 network.
Explain manually configured tunnels
With a manually configured tunnel, tunnel endpoints are configured as point-to-point connections between routers. Requires the routers to be dual-stack, hosts have to be IPv6-only hosts. Works through NAT. Uses static association of an IPv6 address with the IPv4 address of the destination tunnel endpoint. Manual configuration is time-intensive and not recommended for large deployments. Usually chosen when secure site-to-site configurations need to be set up.
Explain 6-to-4 tunneling
Automatic configuration between dual-stack routers at different sites. Hosts can be IPv6 only hosts. Works through NAT. Automatically generates an IPv6 address for the site using the 2002::/16 prefix followed by the public IPv4 address of the tunnel endpoint router. Used to connect IPv6 hosts through IPv4 internet.
Explain ISATAP
Intra-site Automatic Tunnel Addressing Protocol is a tunneling method for use within a site to provide IPv6 communication over a private IPv4 network. Configured between individual hosts and a dual-stack ISATAP router. Clients must be dual-stack or IPv6. Does not work through NAT. Prefix is the link-local FE80::/16, the remaining prefix values are 0. The first two quartets of the interface ID are set to 0000:5EFE and the remaining two are the IPv4 address written in dot-decimal or hexadecimal. Used to begin a transition to IPv6 within a site.
Explain Teredo tunneling
Teredo tunneling establishes the tunnel between individual hosts so they can communicate through a private or public IPv4 network. It is configured between individual dual-stack hosts that tunnel IPv6 to send on IPv4. Works through NAT. Used to enable host-to-host communications between IPv6 devices through a public/private IPv4 network.
What are the main differences between manual configuration, 6-to-4, ISATAP, and Teredo?
Work through NAT: Manually configured, 6-to-4, Teredo Does not work through NAT: ISATAP Site-to-site: manually configured Router-to-router: 6-to-4, ISATAP Host-to-host: Teredo
What is NAT-PT and how is it used?
Network Address Translation-Protocol Translation converts IPv6 packet headers into IPv4 packet headers and vice versa. With NAT-PT, a translation table is reference by the device, such as a Cisco router, as it converts the headers to ensure that the packet is sent to the correct host. This is different from tunneling because headers are converted between IPv4 and IPv6 whereas in tunneling the entire packet is wrapped in the opposing protocol. Configured on a single dual-stack router that allows IPv4 hosts to communicate with IPv6 hosts.
What interface command will allow you to statically assign an interface ID of 0000:0000:0000:0003 to the router interface connected to the 2001:BEDD:FEDD:0002::/64 subnet?
ipv6 address [subnet][interface ID]/64
ipv6 address 2001:BEDD:FEDD:0002::3/64
What interface configuration command would you use to statically assign an interface ID to a router interface connected to the FD01:A001:0001:0008::/64 subnet with the router’s MAC address?
ipv6 address [subnet]/64 eui-64
ipv6 address FD01:A001:0001:0008::/64 eui-64
