10. IPv4 Header

Question 1

The IPv4 header ‘Version’ field is […] bits in length.

Answer 1

4

Question 2

A value of […] in the IP header “Version” field indicates IP version 4

Answer 2

4 (binary 0100)

Question 3

A value of […] in the IP header ‘Version’ field indicates IP version 6.

Answer 3

6 (binary 0110)

Question 4

IPv4 header: What does ‘IHL’ stand for?

Answer 4

Internet Header Length

Question 5

IPv4 header: The ‘IHL’ field is […] bits in length.

Answer 5

4

Question 6

IPv4 Header: The IHL field specifies the length of the header in […] increments.

Answer 6

4-byte (32 bits)

Question 7

IPv4 header: What is the minimum and maximum value of the IHL field?

Answer 7

5 and 15

Question 8

What is the maximum length of the IPv4 header?

Answer 8

60 bytes

Question 9

What is the minimum length of the IPv4 header?

Answer 9

20 bytes

Question 10

IPv4 header: What does ‘DSCP’ stand for?

Answer 10

Differentiated Services Code Point

Question 11

IPv4 header: The ‘DSCP’ field is […] bits in length.

Answer 11

6

Question 12

IPv4 header: Which field is used to prioritize delay-sensitive network traffic?

Answer 12

DSCP (Differentiated Services Code Point)

Question 13

IPv4 header: What does ‘ECN’ stand for?

IPv4 header: The ‘ECN’ field is […] bits in length.

Answer 13

Explicit Congestion Notification - Provides end to end notification of network congestion.
2 bits

Question 14

IPv4 header: The ‘Total Length’ field is […] bits in length.
What is the minimum value of the ‘Total Length’ field?

Answer 14

16
It indicates the total length of the packet.
Min value = 20 (IPv4 header with no encapsulated data)

Question 15

IPv4 header: What is the maximum value of the ‘Total Length’ field?

Answer 15

65,535

Question 16

The ‘Identification’ field is […] bits in length.

Answer 16

16

used to identify which packet a fragment belongs to

Question 17

All fragments of the same packet will have the same value in the […] field.

Answer 17

Identification

Question 18

Pv4 packets are fragmented if they are larger than the […]

Answer 18

MTU (Maximum Transmission Unit) - 1500 bytes

Question 19

The ‘Flags’ field is […] bits in length.

Answer 19

3

Question 20

The ‘Flags’ field is […] bits in length.

Answer 20

3

Question 21

Unfragmented IPv4 packets will always have the MF bit set to […]

Answer 21

0

Question 22

Pv4 header ‘Flags’ field:
Bit […] = Reserved, always set to 0
0

Answer 22

0

Question 23

IPv4 header ‘Flags’ field:

Bit […] = DF bit

Answer 23

1

Question 24

IPv4 header ‘Flags’ field:

Bit […] = MF bit

Answer 24

2

Question 25

IPv4 header: The 'Fragment Offset' field is [...] bits in length.

Answer 25

13

Question 26

Pv4 header: Which field is used to indicate the position of a fragment within an original, unfragmented IP packet?

Answer 26

Fragment Offset

Question 27

IPv4 header: the 'TTL' field is [...] bits in length.

Answer 27

8

Question 28

IPv4 header: the 'TTL' field is [...] bits in length.

Answer 28

8 | used to prevent infinite routing loops

Question 29

The recommended default TTL of an IPv4 packet is [...]

Answer 29

64

Question 30

IPv4 header: The 'Protocol' field is [...] bits in length.

Answer 30

8 | indicates the protocol of the encapsulated L4PDU

Question 31

``` IPv4 header 'Protocol' field: Value of [...] = TCP Value of [...] = UDP Value of [...] = ICMP Value of [...] = OSPF ```

Answer 31

6 17 1 89

Question 32

Pv4 header: the 'Header Checksum' field is [...] bits in length.

Answer 32

16 | used to check for errors in the header

Question 33

The 'Source IP Address' & 'Destination IP Address' field is [...] & [...] bits in length.

Answer 33

32 and 32

Question 34

What is the minimum and maximum length of the 'Options' field?

Answer 34

0 bits 320 bits / 40 bytes