Chapter 8: TCP/IP Applications

Question 1

What is TCP designed for ?

Answer 1

Checking for errors

Question 2

What are three other sessions that use UDP ?

Answer 2

NTP, SNTP, TFTP

Question 3

Domain name system (DNS)

Answer 3

Use of names associated with IP addresses

Question 4

What is DNS’s UDP port number ?

Answer 4

53 by default

Question 5

Does DHCP send information for each step without any confirmation ?

Answer 5

Yes

Question 6

NTP/SNTP

Answer 6

Synchronize the clocks of devices on a network. Operates in hierarchical fashion

Question 7

What is the UDP port number for NTP/SNTP ?

Answer 7

123

Question 8

Stratum servers

Answer 8

Start with stratum 0 (near perfect time) through stratum 15 (devices are not synced with the clock)

Question 9

What other connections does NTP/SNTP employ ? Why ?

Answer 9

Peer-to-peer connections for backups and sanity checks

Question 10

Trivial file transfer protocol (TFTP)

Answer 10

Transfer files with no data protection

Question 11

Typical TFTP usage ?

Answer 11

Update software and configuration on devices on a LAN (routers, switches, VoIP)

Question 12

UDP port number for TFTP ?

Answer 12

69

Question 13

Can an single session consist of a series of packets ?

Answer 13

Yes

Question 14

Firewall

Answer 14

Filters all packets between two computers

Question 15

Ping destination host unreachable ?

Answer 15

No route to address listed or router can’t go forward

Question 16

Ping request timed out ?

Answer 16

Slow network, excess traffic, downed router, etc.

Question 17

Can ping responses be disabled on a target computer ?

Answer 17

Yes

Question 18

Internet group management protocol (IGMP)

Answer 18

Enables routers to communicate with hosts and switches to determine a “group” membership

Question 19

Well-known ports

Answer 19

0 to 1023 reserved for TCP/IP applications

Question 20

Dynamic/ephemeral/private ports

Answer 20

Web client generates a pseduo-randomly source port number, which is used as a destination port for receiving

Question 21

Ephemeral port number range ?

Answer 21

49152-65535

Question 22

Registered ports

Answer 22

Available for anyone to use
1024-49151

Question 23

Socket/endpoint

Answer 23

Session information (IP address, port number, layer 4 protocol) held in memory on a single computer

Question 24

Socket pairs/endpoints

Answer 24

Two computers holding session information in their memory

Question 25

Session

Answer 25

Whole interconnection

Question 26

Netstat

Answer 26

Utility that lists the endpoints of the computers communication