Day 6 Flashcards
Network address translation (NAT)
the function of connecting multiple computers to the internet using one or multiple routable IP addresses
static NAT
designed to allow one to one mapping between local and global addresses
dynamic NAT
gives you the ability to map an unregistered IP addresses to a registered IP address from a pool of registered IP addresses
Port address translation (PAT)
translates local addresses to a single global address by keeping track of port assignments
IPv6
successor of IPv4 128 bits (16 bytes) and 8 segments in length
aggregation
provides a more efficient routing scheme by reducing routing tables
aggregation is an organizational method by which routers are assigned to the subnets of top tier routers
unicast
a packet sent to a unicast address is delivered only to the interface identified by that address
multicast
are similar to the IPv4 broadcast
primarily designed for specific groups of devices
FF02::1 all Nodes address
FF02::2 all Routers address
anycast
addresses assigned to more than one interface and typically on different hosts. a packet sent to an anycast addres is delivered to only one of these interfaces, usually the closes.
(just like the IPv4 anycast, in which the message is sent to the closest interface that has the services it needs)
Unicast Address Types
link-local, global, unique local
link-local
equivalent of IPv4 APIPA addresses.
used as a quick or temporary connection within a network
contains an address prefix and an interface ID
address prefix
FE80::/10
interface ID
identifies a unique interface on a network using the 64-bit extended unique identifier (EUI-64)
converting interface ID to a EUI-64
- split the original 48 bit MAC in half and add FFFE to the middle
- flip the second bit in the first segment
- regroup into 16 bit segments
global
equivalent to IPv4 public addresses and used to route data across.
global unicast address is made of three parts: global routing prefix, subnet ID, and interface ID
unique local address
equivalent of an IPv4 private address
multicast address scopes
multicast traffic is restricted to spheres of influence called scopes
the bigger the scope, the more people it reaches
transitioning to IPv6
dual stacking, translation, and tunnelling
dual stacking
the process of loading both IPv4 and IPv6 on network nodes
translation
dual stack devices can perform translation between IPv6 and IPv4, changing the packet headers for proper communication.
handled by routers
tunneling
the process by which IPv6 packets are encapsulated within IPv4 packets.
handled by routers
Neighbor discovery protocol (NDP)
determines hardware addresses for IPv6 hosts because ARP does not exist in IPv6
Router discovery
IPv6 devices can automatically locate their default gateway.
uses the all routers multicast FF::02 and all nodes multicast address FF02::01
Prefix discovery
router advertisements contain prefix information, which is simply IPv6 subnet information for the local link. once a host knows reachable link prefixes, it can communicate with destinations in those prefixes without first passing that traffic through a router
parameter discovery
adjusting the Maximum Transmission Unit (MTU), allowing host to change the size of the packets
address autoconfiguration
performs stateless autoconfiguration
address resolution
a host needing to know the physical address of a neighbor sends a multicast message called a neighbor solicitation. the neighbor then sends its physical address in a neighbor advertisement response message
next hop determination
next hop determination allows a host to select a default router by performing lookups on the host routing table
Neighbor unreachability detection
NDP is able to determine the reachability of a neighbor
duplicate address detection
used to detect duplicate addresses
redirection
to inform hosts of more preferable routes
DHCPv6
operates in two modes: stateful and stateless
stateful
serves IPv6 addresses, subnet masks, and default gateways
stateless
only serve optional information
DORA is now SARR
works the same, but IPv6 calls the DHCP process SARR…
Solicit, Advertise, Request, and Reply.
only difference between DORA and SARR is if only optional information is needed, only that information will be in the SARR request and reply messages.
test
DORA is now SARR
works the same, but IPv6 calls the DHCP process SARR…
Solicit, Advertise, Request, and Reply.
only difference between DORA and SARR is if only optional information is needed, only that information will be in the SARR request and reply messages.
