CCNA 4.0 - IP Services

Question 1

What two commands are necessary for a telnet/SSH user to see log messages?

Answer 1

1) logging monitor (global config)
2) terminal monitor (exec command)

Question 2

What global config command will store log messages in RAM?

Answer 2

logging buffer

Question 3

What global config command will send log messages to a Syslog server?

Answer 3

logging host (address) (hostname)

Question 4

What command sets the time zone?

Answer 4

clock timezone

Question 5

What command sets daylight savings?

Answer 5

clock summer-time

Question 6

What command configures a device as an NTP server only?

Answer 6

ntp master (stratum-level)

Question 7

What command configured a device as both an NTP server and NTP client?

Answer 7

ntp server (address | hostname)

Question 8

What is the default NTP master stratum level?

Answer 8

8

Question 9

True or false: CDP runs by default.

Answer 9

True

Question 10

The default CDP timer is ____ seconds with a default hold time of ____ seconds.

Answer 10

60, 180

Question 11

What global command enables LLDP on all interfaces?

Answer 11

lldp run

Question 12

Instead of configuring LLDP globally, what commands enable LLDP on an interface?

Answer 12

lldp (transmit | receive)

Question 13

The default LLDP timer is ____ seconds with a default hold time of ____ seconds.

Answer 13

30, 120

Question 14

What command correlates an ACL with a NAT pool? Is this command global or per-interface?

Answer 14

ip nat inside source-list (acl-number) pool (pool-name)

globally configured

Question 15

What command configures a NAT pool?

Answer 15

ip nat pool (name) (first address) (last address) netmask (mask) prefix-length (length)

Question 16

What command enables PAT rather than NAT?

Answer 16

ip nat inside source-list (acl-number) interface (type/number) overload

Question 17

Jitter is defined as…

Answer 17

variations in one-way delay between consecutive packets sent by the same application

Question 18

What are the guidelines for delay, jitter, and loss for voice?

Answer 18

Delay: 150ms or less
Jitter: 30ms or less
Loss: 1% or less

Question 19

What are the guidelines for bandwidth, delay, jitter, and loss for video?

Answer 19

Bandwidth: 384kbps to 20+ Mbps
Delay: 200-400ms
Jitter: 30-50ms
Loss: 0.1% - 1%

Question 20

DSCP stands for…

Answer 20

Differentiated Services Code Point

Question 21

NBAR stands for…

Answer 21

Network Based Application Recognition (an alternative to using ACLs to classify and mark traffic)

Question 22

In what field in the IPv4 header is IPP/DSCP information written?

Answer 22

the ToS (Type of Service) field

Question 23

The DSCP field contains how many bits?

Answer 23

6

Question 24

The three bits of the 802.1Q header at layer 2 goes by two names. What are they?

Answer 24

Class of Service (CoS)
Priority Code Point (PCP)

Question 25

TID is...

Answer 25

The QoS marking field in wifi

Question 26

EXP is...

Answer 26

the QoS marking field over MPLS

Question 27

With regard to trust, a user PC is typically ______ while their IP phone is _____.

Answer 27

Untrusted, trusted

Question 28

By default, Cisco IP phones mark voice packets with what DSCP code?

Answer 28

EF (46) - expedited forwarding

Question 29

By default, Cisco IP phones mark signaling packets with what DSCP code?

Answer 29

CS3

Question 30

What does "Class Selector" represent?

Answer 30

a mapping between older IPP codes and newer DSCP codes

Question 31

Class-Based Weighted Fair Queuing (CBWFQ) works by...

Answer 31

Allocating a specific percentage of guaranteed bandwidth to predefined queues

Question 32

Which is better when shaping: a long time interval or short?

Answer 32

Short - this reduces delay and jitter

Question 33

What command checks for an uncorrupted download of a Cisco IOS executable?

Answer 33

verify - performs an MD5 or SHA512 hash against the file

Question 34

TFTP uses protocol/port...

Answer 34

UDP 69

Question 35

FTP uses protocol/ports...

Answer 35

TCP 20, 21

Question 36

What does traffic shaping do?

Answer 36

It smooths out bursty traffic so that no one particular flow takes up all the available bandwidth

Question 37

What is a syslog facility?

Answer 37

Syslog facilities are ways to organize incoming syslog messages. They are related to components of a system, such as kernel, mail, security, etc.

Question 38

True or false: syslog sends messages in clear text.

Answer 38

True

Question 39

Define QoS "classification."

Answer 39

identification and categorization of network traffic based on criteria like IP address, port number, or protocol

Question 40

Define QoS "marking."

Answer 40

Following classification, packets are marked by DSCP or CoS values to indicate priority.

Question 41

Define QoS "queuing."

Answer 41

Queuing manages the storage of packets within a network device's buffer. It prioritizes packets based on their markings and allows for the efficient handling of traffic flow.

Question 42

Define QoS "congestion avoidance."

Answer 42

proactive measures taken to prevent congestion before it significantly impacts network performance. This can involve techniques like early packet dropping or adaptive queue management.

Question 43

Define QoS "policing."

Answer 43

Policing enforces bandwidth limits on incoming traffic. If a traffic stream exceeds its allocated bandwidth, packets may be dropped or remarked to lower priorities.

Question 44

Define QoS "shaping."

Answer 44

Shaping regulates the outbound traffic rate, ensuring that a device's outgoing traffic stays within its allocated bandwidth. This can involve delaying or buffering packets to smooth out traffic bursts.