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IPV4 Addressing

Subject : it-skills

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What is OSI?
Open Systems Interconnection
National Internet Registry
192.0.2.0/24
60 octets

2. What is the difference between the ToS and the DiffServ byte?
IPv4 and IPv6
RFC 1918
They are the same byte - but the names and value interpretations are different
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)

3. What is the function of ICMP router advertisement and router selection messages?
Destination Unreachable
Uniquely identify every application in the network
255.255.255.252
Used by IRDP on some operating systems to discover local routers

4. What is URG?
LIRs
Largest segment size that the sender is willing to accept
Urgent
255.255.255.240

5. What mechanism is used by TCP to regulate the flow of segments?
Windowing
Used by a host to obtain the IP address associated with another host's MAC address
Don't Fragment
Push

6. What is the IPv4 Protocol number for GRE?
47
Used by IRDP on some operating systems to discover local routers
0
RFC 1918

7. What is NIR?
192.0.2.0/24
Loose source routing; Strict source routing; Record route; Timestamp
National Internet Registry
Router(config-if)#no ip proxy-arp

8. What is the format of the Flags field in the TCP header?
Redirect
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
3
0x0800

9. What TCP/IP protocol suite layer corresponds to the network layer of the OSI model?
All Internet Registries
Internet
DHCP
RIPv1 and IGRP

10. What is prefix /28 in decimal notation?
255.255.255.240
Version (4-bit); Header Length (4-bit); ToS (8-bit); Total Length (16-bit); Identifier (16-bit); Flags (3-bit); Fragment Offset (13-bit); TTL (8-bit); Protocol (8-bit); Header Checksum (16-bit); Source Address (32-bit); Destination Address (32-bit);
4
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111

11. What is the formula to calculate the next Sequence Number based on the Sequence Number of the current TCP segment?
ICANN
Sequence Number + Data payload octets + 1
Transmission Control Protocol
Source Port (16-bit); Destination Port (16-bit); Sequence Number (32-bit); Acknowledgement Number (32-bit); Header Length (4-bit); Reserved (4-bit); Flags (8-bit); Windows Size (16-bit); Checksum (16-bit); Urgent Pointer (16-bit); Options; Padding

12. Who owns the processes by which public IP address space and AS numbers are allocated and assigned?
The next sequence number that the source expects to receive from the destination
ICANN
URG flag set
255.255.255.192

13. Which IPv4 address range is reserved for loopback testing?
0
Destination Unreachable
ICMP Router Discovery Protocol
127.0.0.0/8

14. What is the ARP Operation value for an Inverse ARP Request?
8
Destination Unreachable
Windowing
RIPv1 and IGRP

15. What is LIR?
Padding of zeros to ensure that the header ends on a 32-bit boundary
Number of octets - starting with the octet indicated by the Acknowledgement Number - that the receiver will accept from the sender before the sender must stop transmitting and wait for a new Acknowledgement
Router Advertisement
Local Internet Registry

16. What TCP/IP protocol suite layer corresponds to the session - presentation and application layers of the OSI model?
IANA
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
Application
Congestion Window Reduced

17. What is the format of an IPv4 header?
255.255.255.248
Reserved (1-bit); DF (1-bit); MF (1-bit)
IANA
Version (4-bit); Header Length (4-bit); ToS (8-bit); Total Length (16-bit); Identifier (16-bit); Flags (3-bit); Fragment Offset (13-bit); TTL (8-bit); Protocol (8-bit); Header Checksum (16-bit); Source Address (32-bit); Destination Address (32-bit);

18. How can the receiver determine the size of a packet's data payload based on the IPv4 header?
IANA
Subtract Header Length field from Total Length field
9
Router Selection

19. Who allocates public IP address ranges to NIRs or LIRs?
Final
RIRs
198.18.0.0/15
ICANN and IANA

20. What is ICMP?
Internet Control Message Protocol
Number of octets - starting with the octet indicated by the Acknowledgement Number - that the receiver will accept from the sender before the sender must stop transmitting and wait for a new Acknowledgement
2
192.0.2.0/24

21. What is the prerequisite for using the Urgent Pointer field in the TCP header?
The next sequence number that the source expects to receive from the destination
URG flag set
RFC 3330
Protocols that don't include subnet masks in their routing updates

22. What is the ARP Hardware type value for Ethernet?
1
Router Selection
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
198.18.0.0/15

23. What are the protocol categories that describe the physical layer?
Protocols that include subnet masks in their routing updates
Electrical/Optical - Mechanical - Functional and Procedural
The next sequence number that the source expects to receive from the destination
Padding of zeros to ensure that the header ends on a 32-bit boundary

24. What is the format of the Flags field in the IPv4 header?
198.18.0.0/15
0.0.0.0/8
Reserved (1-bit); DF (1-bit); MF (1-bit)
Used by routers to notify hosts of another router on the data link that should be used for a particular destination

25. What is the format of a TCP header?
IANA
Internet Protocol
Source Port (16-bit); Destination Port (16-bit); Sequence Number (32-bit); Acknowledgement Number (32-bit); Header Length (4-bit); Reserved (4-bit); Flags (8-bit); Windows Size (16-bit); Checksum (16-bit); Urgent Pointer (16-bit); Options; Padding
Hardware type (16-bit); Protocol type (16-bit); Hardware address length (8-bit); Protocol address length (8-bit); Operation (16-bit); Sender hardware address; Sender protocol address; Target hardware address; Target protocol address

26. What is ICMP Type 11?
Time Exceeded
Congestion Window Reduced
Reserved (1-bit); DF (1-bit); MF (1-bit)
Used by a host to obtain the IPv4 address associated with its own MAC address

27. Who is responsible for maintaining the official assignments of TCP and UDP port numbers for specific uses?
URG flag set
IANA
Number of octets - starting with the octet indicated by the Acknowledgement Number - that the receiver will accept from the sender before the sender must stop transmitting and wait for a new Acknowledgement
Padding of zeros to ensure that the header ends on a 32-bit boundary

28. Which IPv4 address range is reserved for use in documentation and example code?
Largest segment size that the sender is willing to accept
192.0.2.0/24
1
Echo

29. What is the first octet rule for IPv4 address classes in binary?
198.18.0.0/15
Loose source routing; Strict source routing; Record route; Timestamp
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
Sequence Number

30. What is the format of the ToS byte in the IPv4 header?
RIRs
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
0x0800

31. What is the recommended default TTL?
Redirect
Router#debug arp
64
Urgent

32. What is the format of an ICMP header?
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
88
DHCP
Padding of zeros to ensure that the header ends on a 32-bit boundary

33. What are the most common IP version numbers?
Push
IPv4 and IPv6
Reset
0.0.0.0/8

34. What is the content of the the Urgent Pointer field in the TCP header?
Uniquely identify every application in the network
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Number of octets to be added to the Sequence Number to indicate the end of the urgent data

35. Who can assign IP address space to end user organizations?
Router(config)#ip arp proxy disable
All Internet Registries
Sequence Number
Acknowledgement

36. What is ICMP Type 9?
3
Router Selection
Echo Reply
Router Advertisement

37. What are the IP Precedence values?
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
Largest segment size that the sender is willing to accept
Subtract Header Length field from Total Length field
Internet Service Provider

38. What is the maximum length of an IPv4 header?
60 octets
ECN-Echo
20 octets
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields

39. Configures how long a dynamically learned protocol address and its corresponding hardware address remains in the ARP cache
Router(config-if)#arp timeout {seconds}
255.255.255.240
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
255.255.255.224

40. What is proxy ARP?
Acknowledgements - checksums and timers
255.255.255.128
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
IANA

41. What is gratuitous ARP?
Largest segment size that the sender is willing to accept
An ARP request issued by a host with its own IPv4 address as the target address
DSCP (6-bit); ECN (2-bit)
Used by a host to obtain the IP address associated with another host's MAC address

42. Which IPv4 address range is reserved for self-identification on a local subnet?
0.0.0.0/8
0x0800
6
RFC 791

43. Who is responsible for the global coordination of the DNS Root - IP addressing - and other Internet protocol resources?
ICANN
Internet Protocol
Protocols that don't include subnet masks in their routing updates
IANA

44. What is RST?
RFC 791
An ARP request issued by a host with its own IPv4 address as the target address
Sequence Numbers
Reset

45. What is the the MF-bit in the IPv4 header?
Length of header in words (32-bit)
Internet
URG flag set
More Fragments follow

46. What TCP/IP protocol suite layer corresponds to the physical and data link layers of the OSI model?
Uniquely identify every application in the network
255.255.255.248
Network interface
2

47. Who group public IPv4 address space by major geographic region?
Router Advertisement
Push
Internet
ICANN and IANA

48. What is a TCP port number of an application called when it is coupled with the IP address of the server?
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
RFC 1918
Socket
Loose source routing; Strict source routing; Record route; Timestamp

49. What is ISP?
Destination Unreachable
Sequence Numbers
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
Internet Service Provider

50. What are the steps to subnet an IPv4 address?
National Internet Registry
Protocols that don't include subnet masks in their routing updates
Mostly large ISPs - enterprises - or academic institutions
1 Determine how many subnets are required; 2 Determine how many hosts per subnet are required; 3 Determine the subnet mask for each subnet; 4 Calculate the network address for each subnet