Chapter 13, Chapter 12 IPv6 Addressing, Chapter 11

What are three parts of an IPv6 global unicast address? (Choose three.)

-a subnet ID that is used to identify networks inside of the local enterprise site. -a global routing prefix that is used to identify the network portion of the address that has been provided by an ISP -an interface ID that is used to identify the local host on the network.

IPv6 Unicast

-The source address must be a unicast address. -types: Global Unicast (GUA) Link-local address (LLA) Loopback Unspecified Address Unique Local Embedded IPv4

Network Host portions

-IPv4 addresses are made of 32 bits of zeros and ones. -All devices on the same network must have the Network portion of their address for all devices on that network. -The host portion must be unique for each address.

What type of IPv6 address begins with fe80?

-LLA

IPv4 portions

-Made up of three parts Network, Host, broadcast -Network portion, starts at left side. -Host portion remaining part not part of network portion. -reserved addresses network (lowest)and broadcast address (highest).

methods of RA messages

-Method 1 SLAAC -Method 2 SLAAC with a stateless DHCPv6 server -Method 3 Stateful DHCPv6 (no SLAAC)

What are the two methods a device can use to generate its own IPv6 interface ID?

-Randomly generated -EUI-64

Which devices will not forward an IPv4 broadcast packet by default?

-Router

Which two situations are the result of excessive broadcast traffic? (Choose two)

-Slow network operations -Slow device operations

Loopback Addresses

-Special addresses that are used by a host to direct traffic to itself. -used for testing if the TCP/IP configuration is operational. -loop back address 127.0.0.1 subnet 172.255.255.254

Which field in an IPv6 GUA is used for subnetting?

-Subnet ID

Which utility uses the Internet Control Messaging Protocol (ICMP)?

-ping

True or False: The Subnet ID field in an GUA must borrow bits from the interface ID.

-False

Which part of a GUA is assigned by the ISP?

Global Routing Prefix

What is the recommended prefix length for most IPv6 subnets?

-/64

Hextet

-16 bits of information. - omit leading zeros example 01ab is displayed as 1ab or 00ab =ab

The Subnet Mask

Used to identify the network/host portion of the IPv4 address -The process of looking for the network and host portion of the IPv4 address is called ANDing. -The prefix length is a method of identifying the network and host portions of the address.

Which type of IPv6 address is not routable and used only for communication on a single subnet?

link-local address

Subnetting

The act of dividing a network into smaller logical subnetworks. -Borrowing a bit of the host address in an IPv4 address to use as a subnet bit. Side affect is it will reduce the available host addresses. subnet bits 2^1= 2 host bits = 2^7 = 126 subnetworks = 2

default gateway address

The address of the computer that provides a connection to the Internet. -IPv6 LLA, the source IPv6 address of the RA message.

ipv6 unicast-routing

a command to enable IPv6 on a router as routers are not enabled to route IPv6 addresses by default and must first be enabled.

Unicast

a form of message delivery in which a message is delivered to a single destination - one to one communications

Which command can be used to test connectivity between two devices using echo request and echo reply messages?

ping

Which ICMP message is used by the traceroute utility during the process of finding the path between two end hosts?

time exceeded

A network administrator can successfully ping the server at www.cisco.com, but cannot ping the company web server located at an ISP in another city. Which tool or command would help identify the specific router where the packet was lost or delayed?

traceroute

A technician is troubleshooting a network where it is suspected that a defective node in the network path is causing packets to be dropped. The technician only has the IP address of the end point device and does not have any details of the intermediate devices. What command can the technician use to identify the faulty node?

tracert

Boadcast

- A message sent to all devices on the network. -IPv4 uses broadcast packets. however there are no broadcast packets with IPv6 -broadcasting causes all devices to process the packet which can be resource intensive. -255.255.255.255 is a broadcast address. -To avoid malicious use, broadcast addresses are turned off by default as per Cisco IOS release 12.0 (no ip directed-broadcasts)

The Prefix Length

- The number of bits set to 1 in the subnet mask. -written in slash notation(/). -example 192.168.10.10 255.255.255.0 would be 192.168.10.10/24 because 255.255.255.0 = 11111111.11111111.11111111.00000000 8 16 24 so 255.255.255.0 = 24 and IP 192.168.10.10 with subnet = 192.168.10.10/24

VLSM

- Variable Length Subnet Masking - You do not need to subnet mask equally, you can choose to subnet your available IP address in to segments of different size subnets.

Internet Assigned Numbers Authority IANA

- allocates blocks of IP addresses for use on the internet.

Rules for IPv6 notation

- omit leading zeros example 01ab is displayed as 1ab or 00ab =ab -Double Colon example: 2001:db8:cafe:1:0:0:0:1 = 2001:db8:cafe:1::1 Double colon is only allowed once in an IPv6 address.

What is the minimum configuration for a router interface that is enabled for IPv6?

- to have a link-local IPv6 address

Which two statements are correct about private IPv4 addresses? (Choose two.)

-10.0.0.0/8 is a private network and can be used by any school, home, or office for internal networking. -Private IPv4 are assigned to devices within an organization's intranet.

Given a /48 Global Routing Prefix and a /64 prefix, what is the subnet portion of the following address: 2001:db8:cafe:1111:2222:3333:4444:5555

-1111

Your organization is issued the IPv6 prefix of 2001:db8:130f::/48 by your service provider. With this prefix, how many bits are available for your organization to create /64 subnetworks if interface ID bits are not borrowed?

-16

What is the prefix associated with the IPv6 address 2001:DB8:D15:EA:CC44::1/64?

-2001:DB8:D15:EA::/64

What is the network address for the IPv6 address 2001:DB8:AA04:B5::1/64?

-2001:DB8AA04:B5

What is the most compressed representation of the IPv6 address 2001:0db8:0000:abcd:0000:0000:0000:0001?

-2001:db8:0:abcd::1

What is the interface ID of the IPv6 address 2001:DB8::1000:A9CD:47FF:FE57:FE94/64?

-A9CD:47FF:FE57:FE94

Which IPv6 network prefix is only intended for local links and can not be routed?

-FE80::/10

True or False. RA messages are sent to all IPv6 routers by hosts requesting addressing information.

-False

Which protocol is used by IPv4 and IPv6 to provide error messaging?

-ICMP

What is indicated by a successful ping to the ::1 IPv6 address?

-IP is properly installed on the host

What is the purpose of the command ping ::1?

-It tests the internal configuration of an IPv6 host.

Which type of IPv6 unicast address is not routable between networks?

-LLA

Which dynamic addressing method for GUAs is the one where devices rely solely on the contents of the RA message for their addressing information?

-Method 1 :SLAAC

Which dynamic addressing method for GUAs is the one where devices rely solely on a DHCPv6 server for their addressing information?

-Method 3: Stateful DHCPv6

ICMP Messages

-TCP/IP suite provides for error messages and informational messages sent using ICMP when communicating with another IP device. -ICMP messages common to IPv4 and IPv6 is: Host reachability, Destination or Service Unreachable, time exceeded.

A user calls to report that a PC cannot access the internet. The network technician asks the user to issue the command ping 127.0.0.1 in a command prompt window. The user reports that the result is four positive replies. What conclusion can be drawn based on this connectivity test?

-The TCP/IP implementation is functional.

What is a function of the tracert command that differs from the ping command when they are used on a workstation?

-The tracert command shows the information of routers in the path.

A user who is unable to connect to the file server contacts the help desk. The helpdesk technician asks the user to ping the IP address of the default gateway that is configured on the workstation. What is the purpose for this ping command?

-To test that the host has the capability to reach hosts on other networks.

True or False? IPv6 was designed with subnetting in mind.

-True

Ping and Traceroute Testing

-Uses ICMP echo requests and echo reply messages to test connectivity between hosts. Can be used to test internal configuration of hosts. -A successful ping to the default gateway will indicate both the router and host are operational.

Multicast

-a form of transmission in which a message is delivered to a group of hosts. -IPv4 uses 224.0.0.0-239.255.255.255 -Routing protocols such as OSPF use multicast transmissions. -when an IPv4 host subscribes to a multicast group, the host processes packets addressed to this multicast address, and the packets addressed to its uniquely allocated unicast address.

Which address type is not supported in IPv6?

-broadcast

Legacy Classful Addressing

-classes were assigned to IP addresses depending on if the computers on the internet would need more than others. A uses the most IP range, B second most, and so on until D and E which use the least. Class A 0.0.0.0/8-127.0.0.0/8 Class B 128.0.0.0/16-191.255.0.0/16 Class C 192.0.0.0/24-223.255.255.0/24

At a minimum, which address is required on IPv6-enabled interfaces?

-link-local

What type of address is automatically assigned to an interface when IPv6 is enabled on that interface?

-link-local

Which dynamic addressing method for GUAs is the one where devices get their IPv6 configuration in a RA message and request DNS information from a DHCPv6 server?

-method : SLLAC and Stateless DHCPv6

Which two statements are correct about public IPv4 addresses? (Choose two.)

-only addresses that are public may be used to access the internet. Public IPv4 address exhaustion is the reason why IPv6 is being transitioned to.

Public and Private IPv4 Addresses

-some addresses are not allowed on the internet while others are only allowed on the internet. -Public IP addresses are assigned and used globally by ISP Internet service providers. -Private addresses are not unique and remain on the network and are not used on the internet. -Private addresses are sometimes referred to as RFC 1918 address space. -When a private IP needs to send information over the internet, the router will replace the private ip address with a public IP address for that purpose. It will discard the private IP address in this process. -Private Address Blocks 10.0.0.0/8 subnet mask 255.0.0.0 172.16.0.0/12 subnet mask 255.240.0.0 192.168.0.0/16 subnet mask 255.255.0.0

Which two things can be determined by using the ping command? (Choose two.)

-the average time it takes a packet to reach the destination and for the response to return to the source. -the destination device is reachable through the network.

A network administrator is testing network connectivity by issuing the ping command on a router. Which symbol will be displayed to indicate that a time expired during the wait for an ICMP echo reply message?

.

Logical AND

1 = 1 True 1 = 0 False 0 = 1 False 0 = 0 False

For IPv6 given a /32 Global Routing Prefix and a /64 prefix, how many bits would be allocated for the Subnet ID? 8 16 32 48 64

32

Network Segmentation

A network arrangement in which some portions of the network have been separated from the rest of the network in order to protect some resources while granting access to other resources.

host and network portion example

IPv4 192.168.10.10 = 11000000. 10101000.00001010.00001010 subnet 255.255.255.0 = 111111111.11111111.11111111.00000000 example: 192 ip= 1 1 0 0 0 0 0 0 subnet= 1 1 1 1 1 1 1 1 Logical AND = 1 1 0 0 0 0 0 0

What message is sent by a host to check the uniqueness of an IPv6 address before using that address?

NS neighbor solicitation

Which organization or group of organizations receives IP addresses from IANA and is responsible for allocating these addresses to ISPs and some organizations?

Reginal Internet Registries (RIR)

RS and RA messages

Router Advertisement (RA) messages. -ICMPv6 can dynamically assign the GUA address. - RS messages are sent to to IPv6 routers by their hosts, this message is requesting addressing information. RA messages are set to all IPv6 nodes.

IPv6 commands

Similar to those of IPv4 commands. The IPv6 version of ip address for example is ipv6 address.

network prefix and prefix length

Tells the device which network it belongs to.

Which protocol provides feedback from the destination host to the source host about errors in packet delivery?

ICMP

What field content is used by ICMPv6 to determine that a packet has expired?

Hop Limit field