Module 8 CNG
What destination UDP port do DHCPv6 clients use to send DHCPv6 messages?
546
What are the flag settings when a host should use the SLAAC only option?
A=1 , M=0, O=0
What flag settings combination is used for stateless DHCP?
A=1, M=0, O=1
What method is used by a host to verify an IPv6 address is unique on the local network before assigning that address to an interface?
DAD
What process is used in ICMPv6 for a host to verify that an IPv6 address is unique before configuring it on an interface?
DAD
A company implements the stateless DHCPv6 method for configuring IPv6 addresses on employee workstations. After a workstation receives messages from multiple DHCPv6 servers to indicate their availability for DHCPv6 service, which message does it send to a server for configuration information?
DHCPv6 INFORMATION-REQUEST
Which three DHCPv6 roles can a router perform? (Choose all that apply.)
DHCPv6 client DHCPv6 relay agent DHCPv6 server
The host creates an interface ID using its 48-bit MAC address. The host inserts the hex value of fffe in the middle of the address, and flips the seventh bit of the interface ID. This changes the value of the second hexadecimal digit of the interface ID. Some operating systems default to the randomly generated interface ID instead of the EUI-64 method, due to privacy concerns. This is because the Ethernet MAC address of the host is used by EUI-64 to create the interface ID.
EUI-64 - T
Which destination IP address is used when an IPv6 host sends a DHCPv6 SOLICIT message to locate a DHCPv6 server?
FF02::2
DAD is implemented using ____________.
ICMPv6
To perform DAD, the host sends an __________________________ message with a specially constructed ____________________ address, called a _______________________________. This address duplicates the________________________________ of the host.
ICMPv6 Neighbor Solicitation (NS) multicast solicited-node multicast address last 24 bits of IPv6 address
When automatic IPv6 addressing is selected, what will the host attempt to automatically obtain and configure on the interface?
IPv6 address information
What are two characteristics of the SLAAC method for IPv6 address configuration? (Choose two.)
IPv6 addressing is dynamically assigned to clients through the use of ICMPv6 The default gateway of an IPv6 client on a LAN will be the link-local address of the router interface attached to the LAN
When automatic IPv6 addressing is selected, the host will use one of three methods defined by the ______________________________________________ received on the interface.
Internet Control Message Protocol version 6 (ICMPv6) Router Advertisement (RA) message
The ______________________________recommends that DAD is used on all IPv6 unicast addresses regardless of whether it is created using SLAAC only, obtained using stateful DHCPv6, or manually configured.
Internet Engineering Task Force (IETF)
Which command should be configured on a router interface to set the router as a stateful DHCPv6 client?
Ipv6 address dhcp
A network administrator is entering the command ipv6 unicast-routing to start configuring DHCPv6 operation on a router. Which statement describes the function of this command?
It is required for sending ICMPv6 RA messages
A client is using SLAAC to obtain an IPv6 address for its interface. After an address has been generated and applied to the interface, what must the client do before it can begin to use this IPv6 address?
It must send an ICMPpv6 Neighbor Solicitation message to ensure that the address is not already in use on the network
How does an IPv6 client ensure that it has a unique address after it configures its IPv6 address using the SLAAC allocation method?
It sends an ICMPv6 Neighbor Solicitation message with the IPv6 address as the target IPv6 address
What M flag setting indicates that stateful DHCPv6 is used?
M=1
What is the DHCPv6 server doing in stateless?
No device is tracking the assignment of IPv6 addresses
The decision of how a client will obtain an IPv6 GUA depends on the settings within the _____________________
RA message.
An IPv6 router that is on the same link as the host sends out ____________________ that suggest to the hosts how to obtain their IPv6 addressing information.
RA messages
What DHCPv6 message does a host send to the DHCPv6 server if it is using stateful DHCPv6?
REQUEST
DHCPv6 is defined in ?
RFC 3315.
The 64-bit interface ID is randomly generated by the client operating system. This is the method now used by Windows 10 hosts.
Randomly generated -
A host can also send a _________________________message requesting that an IPv6-enabled router send the host an RA.
Router Solicitation (RS)
Which ICMPv6 message is sent by a host in an attempt to locate an online IPv6enabled router to obtain IPv6 addressing information?
Router Solicitation (RS)
Which two ICMPv6 messages are used in the SLAAC process? (Choose two.)
Router Solicitation (RS) Router Advertisements (RA)
DHCPv6 Client
Router interface acquires an IPv6 IP configuration from a DHCPv6 server.
DHCPv6 Relay Agent -
Router provides DHCPv6 forwarding services when the client and the server are located on different networks.
DHCPv6 Server
Router provides stateless or stateful DHCPv6 services.
In which alternative to DHCPv6 does a router dynamically provide IPv6 configuration information to hosts?
SLAAC
______________ and _______________ are dynamic addressing protocols for an IPv6 network
SLAAC DHCPv6
Which method best describes stateless DHCP?
SLAAC with stateless DHCPv6 Server
What DHCPv6 message does a host send to look for a DHCPv6 server?
SOLICIT
What DHCPv6 does not require SLAAC?
Stateful
What DHCPv6 uses parts of SLAAC to ensure that all the necessary information is supplied to the host?
Stateless
Which command is not configured in stateless DHCPv6?
address-prefix ipv6-address/prefix
On a router, what is manually configured using the ipv6 address ipv6-address/prefix-length interface configuration command?
an IPv6 global unicast address (GUA)
When a client is configured to obtain its addressing information automatically, it sends an RS message to the IPv6 all-routers multicast address of _________________
ff02::2.
What does the SLAAC method enable?
hosts to create their own unique IPv6 global unicast address without the services of a DHCPv6 server.
An IPv6 router that is on the same link as the host sends out RA messages, what do these messages suggest to the hosts?
how to obtain their IPv6 addressing information.
what is in the RA?
includes the prefix, prefix-length, DNS server, MTU, and default gateway information.
An IPv6-enabled router is to acquire its IPv6 GUA from another IPv6 router using SLAAC. Which interface configuration command should be configured on the client router?
ipv6 address autoconfig
An IPv6-enabled router is to acquire its IPv6 GUA from a DHCPv6 server. Which interface configuration command should be configured on client router?
ipv6 address dhcp
Which command is configured on the client LAN interface of the DHCPv6 relay agent?
ipv6 dhcp relay destination
A router is to provide DHCPv6 server services. Which command should be configured on the client facing interface?
ipv6 dhcp server POOL-NAME
Stateless DHCPv6 is enabled on a router interface using the_______________________________ interface configuration command. This sets the O flag to 1.
ipv6 nd other-config-flag
The SLAAC only method is enabled by default when the ____________________ command is configured.
ipv6 unicast-routing
Which command must be configured on a router to enable it to join the IPv6 all-routers multicast address ff02::2?
ipv6 unicast-routing
What is the DHCPv6 server doing in stateful?
it is managing the assignment of the IPv6 addresses
Using SLAAC, a host typically acquires _______________________________ However, it must generate the remainder ___________________________ using one of two methods:
its 64-bit IPv6 subnet information from the router RA. 64-bit interface identifier (ID)
The IPv6 ______________________ is automatically created by the host when it boots and the Ethernet interface is active.
link-local address
Which address type is automatically created by default on a host interface when no RAs are received?
link-local address
What two methods can be used to generate an interface ID by an IPv6 host that is using SLAAC? (Choose two.)
random generation EUI-64
Windows, Linux, and Mac OS allow for the user to modify the generation of the interface ID to be either ____________________ or to use ____________________
randomly generated EUI-64.
Which method would an IPv6-enabled host using SLAAC employ to learn the address of the default gateway?
router advertisements that are received from the link router
Which DHCPv6 verification command would display the link-local and GUA assigned address for each active client?
show ipv6 dhcp binding
The ______________________ command verifies the name of the DHCPv6 pool and its parameters. The command also identifies the number of active clients.
show ipv6 dhcp pool
SLAAC is a _________________ service.
stateless
What does the A = 1 flag suggest to the client?
that it create its own IPv6 GUA using the prefix advertised in the RA. The client can create its own Interface ID using either Extended Unique Identifier method (EUI-64) or have it randomly generated.
On a router, an IPv6 global unicast address (GUA) is manually configured using what command?
the ipv6 address ipv6-address/prefix-length interface configuration command.
An ICMPv6 RA message includes _______________ flags to identify the dynamic options available to a host
three
What do the O =0 and M=0 flags instruct the client?
to use the information in the RA message exclusively.
SLAAC is a stateless process; therefore, a host has what option?
to verify that a newly created IPv6 address is unique before it can be used.
RA messages are sent by an IPv6 router every _____________ seconds.
200
What process is used by a host to ensure that the IPv6 GUA is unique.?
The Duplicate Address Detection (DAD)
What message informs IPv6 enabled interfaces to use stateful DHCPv6 for obtaining an IPv6 address?
The ICMPv6 Router Advertisement
After booting, a client receives an ICMPv6 RA message with the M flag set to 0 and the O flag set to 1. What does this indicate?
The client should automatically configure an IPv6 address and then contact a DHCPv6 server for more information
The steps for DHCPv6 operations are as follows:
The host sends an RS message. The router responds with an RA message. The host sends a DHCPv6 SOLICIT message. The DHCPv6 server responds with an ADVERTISE message. The host responds to the DHCPv6 server. The DHCPv6 server sends a REPLY message.
A flag
This is the Address Autoconfiguration flag. Use Stateless Address Autoconfiguration (SLAAC) to create an IPv6 GUA.
M flag
This is the Managed Address Configuration flag. Use a stateful DHCPv6 server to obtain an IPv6 GUA.
O flag
This is the Other Configuration flag. Other information is available from a stateless DHCPv6 server.
What does it mean when SLAAC is a stateless service?
This means there is no server that maintains network address information to know which IPv6 addresses are being used and which ones are available.
Host operating systems will at times show a link-local address appended with a "%" and a number, what is this known as?
a Zone ID or Scope ID. It is used by the OS to associate the LLA with a specific interface.