CCNA2 Module 3 (Netacad Module 8)

What UDP port do DHCPv6 clients use to send DHCPv6 messages?

547

What is a Link-Local Unicast Address?

A *Link-Local Unicast Address* is an address that begins with fe80::/10 and *ALL* interfaces must have one. This address is not routable off the link and only needs to be unique on a per-link basis. Only one Link-Local address is allocated per interface.

What are the 3 flags in a RA message?

A flag - This is the Address Autoconfiguration flag. Use Stateless Address Autoconfiguration (SLAAC) to create an IPv6 GUA. O flag - This is the Other Configuration flag. Other information is available from a stateless DHCPv6 server. M flag - This is the Managed Address Configuration flag. Use a stateful DHCPv6 server to obtain an IPv6 GUA.

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 Server DHCPv6 relay agent DHCPv6 server

What two methods can be used to generate an interface ID by an IPv6 host that is using SLAAC? (Choose two.)

EUI-64 random generation

Which destination IP address is used when an IPv6 host sends a DHCPv6 SOLICIT message to locate a DHCPv6 server?

FF02::1:2

What message informs IPv6 enabled interfaces to use stateful DHCPv6 for obtaining an IPv6 address?

ICMPv6 Router Advertisement with the managed configuration flag (M flag) set to 1.

What M flag setting indicates that stateful DHCPv6 is used?

M=1

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.) Neighbor Advertisements (NA) Neighbor Solicitation (NS) Router Solicitation (RS) Router Advertisements (RA)

Router Solicitation (RS) Router Advertisements (RA)

What are the steps to configure a router as a relay agent?

Router(config-if)# ipv6 dhcp relay destination ipv6-address [interface-type interface-number]

Which method best describes stateless DHCP?

SLAAC with stateless DHCPv6 Server

How does DAD work?

Sends an NS message with a specially constructed multicast address, called a solicited-node multicast address. This address duplicates the last 24 bits of IPv6 address of the host. If it receives a response, duplicate address If no response, can use the address

What DHCPv6 message does a host send to look for a DHCPv6 server?

Solicit

In which alternative to DHCPv6 does a router dynamically provide IPv6 configuration information to hosts?

Stateless Address Autoconfiguration (SLAAC)

What are the 5 steps to configure and verify a router as a stateful DHCPv6 client?

Step 1. Enable IPv6 routing. Step 2. Configure the client router to create an LLA. Step 3. Configure the client router to use DHCPv6. Step 4. Verify that the client router is assigned a GUA. Step 5. Verify that the client router received other necessary DHCPv6 information.

What are the 5 steps to configure and verify a router as a stateless DHCPv6 client?

Step 1. Enable IPv6 routing. Step 2. Configure the client router to create an LLA. Step 3. Configure the client router to use SLAAC. Step 4. Verify that the client router is assigned a GUA. Step 5. Verify that the client router received other necessary DHCPv6 information.

What are the 5 steps to configure and verify a router as a stateful DHCPv6 server?

Step 1. Enable IPv6 routing. Step 2. Define a DHCPv6 pool name. Step 3. Configure the DHCPv6 pool. Step 4. Bind the DHCPv6 pool to an interface. Step 5. Verify that the hosts have received IPv6 addressing information.

What are the 5 steps to configure and verify a router as a stateless DHCPv6 server?

Step 1. Enable IPv6 routing. Step 2. Define a DHCPv6 pool name. Step 3. Configure the DHCPv6 pool. Step 4. Bind the DHCPv6 pool to an interface. Step 5. Verify that the hosts have received IPv6 addressing information.

Which method would an IPv6-enabled host using SLAAC employ to learn the address of the default gateway?

a host will learn from the router advertisement that is sent by the link router the address to use as a default gateway.

Which command is not configured in stateless DHCPv6?

address prefix ipv6-address/prefix

What does the show ipv6 dhcp binding command do?

display the IPv6 link-local address of the client and the global unicast address assigned by the server.

What does the ipv6 enable command do?

enables IPv6 on an interface and allows the router to configure its link-local address.

What does the ipv6 address dhcp command do?

enables the router as a DHCPv6 client on this interface.

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?

host should automatically configure its own IPv6 interface address rather than asking for one from a DHCPv6 server. If the O flag is set to 1, it means that the client can find additional addressing information, such as a DNS server address, by contacting a DHCPv6 server after it has automatically configured its own address.

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

Which command should be configured on a router interface to set the router as a stateful DHCPv6 client?

ipv6 address autoconfigure

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

Which command must be configured on a router to enable it to join the IPv6 all-routers multicast address ff02::2?

ipv6 unicast-routing

How is the IPv6 GUA configured on a router?

it is manually configured using the ipv6 address command.

Which address type is automatically created by default on a host interface when no RAs are received?

link-local address

What is duplicate address detection (DAD)?

process is used by a host to ensure that the IPv6 GUA is unique.

What DHCPv6 message does a host send to the DHCPv6 server if it is using stateful DHCPv6?

request

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?

required for sending ICMPv6 RA messages.

How does an IPv6 client ensure that it has a unique address after it configures its IPv6 address using the SLAAC allocation method?

send an ICMPv6 Neighbor Solicitation message with its own IPv6 address as the target.

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?

sending out an ICMPv6 Neighbor Solicitation message and listening for a response.

Which DHCPv6 verification command would display the link-local and GUA assigned address for each active client?

show ipv6 dhcp binding

How can a relay agent be verified?

show ipv6 dhcp interface command

What does the ipv6 address autoconfigure do? command do?

tells the router to use either SLAAC or stateless DHCPv6 to configure its global unicast address.

What are two characteristics of the SLAAC method for IPv6 address configuration? (Choose two.)

the default gateway for IPv6 clients will be the link-local address of the router interface that is attached to the client LAN. IPv6 addressing is dynamically assigned via the ICMPv6 protocol.

What is the default gateway for IPv6 clients using SLAAC?

the link-local address of the router interface that is attached to the client LAN

What does the DHCPv6 ADVERTISE message do?

used by DHCPv6 servers to indicate their availability for DHCPv6 service.

What does the DHCPv6 SOLICIT message do?

used by a client to locate a DHCPv6 server.

What does the DHCPv6 REQUEST message do?

used by a client, in the stateful DHCPv6 configuration, to request ALL configuration information from a DHCPv6 server.

What does the ipv6 dhcp server command do?

used on a router that is running a DHCPv6 server to indicate what address information should be served to clients.

What does the show ipv6 dhcp pool command do?

verifies the name of the DHCPv6 pool and its parameters. The command also identifies the number of active clients.

What are the 6 steps for DHCPv6 operation?

1. The host sends an RS message. 2. The router responds with an RA message. 3. The host sends a DHCPv6 SOLICIT message. 4. The DHCPv6 server responds with an ADVERTISE message. 5. The host responds to the DHCPv6 server. 6. The DHCPv6 server sends a REPLY message.

What port do server to client DHCPv6 messages use?

UDP port 546

What port do client to server DHCPv6 messages use?

UDP port 547