Chp 6. Intro to Networking

Question 1

The network layer provides services to allow end devices to exchange data across the network. To accomplish this end-to-end transport, the network layer uses four basic processes:

Answer 1

• Addressing end devices
• Encapsulation
• Routing
• De-Encapsulation

Question 2

The network layer encapsulates the protocol data unit (PDU)

Answer 2

from the transport layer into a packet.

Question 3

Each router a packet crosses to reach the destination host is called

Answer 3

a hop.

Question 4

Does the IP Header remain the same from the time the packet leaves the source host until it arrives at the destination host?

Answer 4

Yes

Question 5

Best Effort IP Characteristics: (2)

Answer 5

Packet delivery is not guaranteed The packet may be delivered with errors

Question 6

The header Differentiated Services or DiffServ (DS) field is an

Answer 6

is an 8-bit field used to determine the priority of each packet.

Question 7

The header Time-to-Live (TTL) field

Answer 7

Contains an 8-bit binary value that is used to limit the lifetime of a packet.

Question 8

What happens if the TTL field decrements to zero?

Answer 8

the router discards the packet and sends an Internet Control Message Protocol (ICMP) Time Exceeded message to the source IP address

Question 9

The header Protocol Field is an 8-bit binary value that

Answer 9

indicates the data payload type that is being carried, which enables the network layer to pass the data to the appropriate upper-layer protocol.

Question 10

IPv4 still has three major issues:

Answer 10

• Address Depletion
• Internet Routing and Table Expansion
• Lack of end-to-end connectivity

Question 11

Ipv6 improvements to Ipv4 (5)

Answer 11

• Improved Packet Handling
• Larger Payload for increased throughput
• Hierarchical Architecture for routing efficiency
• Autoconfiguration for addresses
• No Need for Nat

Question 12

IPv6 Packet Header: Flow Label - This 20-bit field suggests that all packets with the same flow label receive

Answer 12

the same type of handling by routers.

Question 13

IPv6 Packet Header: Next Header - This 8-bit field is equivalent to the IPv4 Protocol field.

Answer 13

Identifies the application type to the upper-layer protocols

Question 14

IPv6 Packet Header: Hop Limit - This 8-bit field replaces the IPv4

Answer 14

Time To Live (TTL) field.

Question 15

IPv6 Packet Header: Traffic Class

Answer 15

Classifies packets for congestion control

Question 16

On a Cisco IOS router, which command can be used to display the router’s IPv4 routing table

Answer 16

show ip route

Question 17

When a router interface is configured with an IPv4 address, a subnet mask, and is activated, the following two routing table entries are automatically created:

Answer 17

C - Identifies a directly-connected network

L - Identifies that this is a local interface.

Question 18

C - Identifies a directly-connected network. Directly-connected networks are automatically created when

Answer 18

an interface is configured with an IP address and activated

Question 19

L - Identifies that this is a local interface.

Answer 19

This is the IPv4 address of the interface on the router.

Question 20

What are the three Routing Table entries you need to know

Answer 20

Route Source Destination Network Outgoing Interface

Question 21

Routing Source identifies how the

Answer 21

network was learned by the router

Question 22

Outgoing interface identifies the exit

Answer 22

interface to forward a packet toward the final destination

Question 23

Route TimeStamp Identifies

Answer 23

when the router was last heard from

Question 24

Next Hop Identifies

Answer 24

the IP address of the next router to forward the packet.

Question 25

Aux Port

Answer 25

A port to manage routers using telephone lines and modems

Question 26

Switch Configuration Commands

Answer 26

Switch Configuration Tasks Commands

Question 27

Configure the device name (1)

Answer 27

Switch> enable

Switch# configure terminal

Switch(config)# hostname rayswitch

Question 28

Commands to Secure access to console port aka

Secure user EXEC mode (3)

Answer 28

Switch> enable

Switch# configure terminal

Switch(config)# line console 0

Switch(config)# password cisco

Switch(config)# login

Question 29

Secure Remote Telnet/SSH Access (3)

Answer 29

Switch> enable

Switch# configure terminal

Switch(config)# line vty 0 15

Switch(config)# password cisco

Switch(config)# login

Question 30

Secure Privileged Exec Mode: (1)

Secure all passwords in the config file: (1)

Answer 30

Switch(config)# enable secret password

Switch(config)# service password-encryption

These are usually turned on at the same time

Question 31

Provide Legal Notification aka banner message (1)

Answer 31

Switch> enable

Switch# configure terminal

Switch(config)# banner motd ” Place the keep out message here”

Question 32

Configure VLANS (Remote access) or Configure the management SVI

Answer 32

Switch> enable

Switch# configure terminal

Switch(config)# interface vlan 1

Switch(config)# ip address 10.18.0.19 255.255.255.0

Switch(config)# no shutdown

Switch(config)# end

Question 33

Save Running Configuration

Answer 33

R1# copy running-config startup-config

Question 34

What is not required but good practice to perform when configuring a networking device?

Answer 34

configure a description on each interface to help document the network information.

The description text is limited to 240 characters.

Question 35

Commands to add a description to router aka as adding documentation (4)

Answer 35

R1# conf t

R1(config)# interface type_space_number

R1(config)# ip address subnet mask

R1(config)# description anything you type afte description will show up on scree,

R1(config)# no shutdown

Exp: interface gigabitethernet 0/0

Question 36

What do the coded int the IPv4 routing table codes in the comman line:

C – ?

S – ?

D – ?

* – ?

Answer 36

C – directly connected

S – static

D – EIGRP

* – candidate default

Question 37

Which two pieces of information are in the RAM of a Cisco router during normal operation?

Answer 37

• The IP routing table
• The Cisco IOS file is stored in flash memory and copied into RAM during the bootup.

Question 38

Startup configuration file in a cisco router is stored in..

Answer 38

NVRAM

Question 39

The connections in a Cisco 1941 router include two types of ports that are used for initial configuration and command-line interface management access. The two ports are the regular RJ-45 port and a new USB Type-B (mini-B USB) connector. In addition, the router has an AUX port for remote management access, and two Gigabit Ethernet interfaces for LAN access. Compact Flash can be used increase device storage, but it does not perform the functions of the CPU, which is required for operation of the device.

Question 40

What are two types of router interfaces?

Answer 40

LAN interfaces – Used for connecting routers to each other.
WAN interfaces – Used for connecting routers to external networks, usually over a larger geographical distance.

Question 41

A router boots and enters setup mode. What is the reason for this?

The configuration file is missing from NVRAM.

Question 42

When a connectionless protocol is in use at a lower layer of the OSI model, how is missing data detected and retransmitted if necessary?

Answer 42

Upper-layer connection-oriented protocols keep track of the data received and can request retransmission from the upper-level protocols on the sending host.