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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 the format of the Flags field in the IPv4 header?
Reserved (1-bit); DF (1-bit); MF (1-bit)
8
RIRs
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);

2. What is TCP?
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
Transmission Control 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
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)

3. What TCP/IP protocol suite layer corresponds to the session - presentation and application layers of the OSI model?
6
Router(config-if)#arp timeout {seconds}
Application
Final

4. What is the ARP Hardware type value for Ethernet?
IANA
ICANN
Per-Hop Behaviour (PHB)
1

5. What is the first octet rule for IPv4 address classes in binary?
Echo Reply
Padding of zeros to ensure that the header ends on a 32-bit boundary
255.255.255.128
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111

6. What is a TCP port number of an application called when it is coupled with the IP address of the server?
Socket
IANA
LIRs
20 octets

7. What are the most frequently used options in the IPv4 header?
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
Acknowledgements - checksums and timers
ECN-Echo
Loose source routing; Strict source routing; Record route; Timestamp

8. What is prefix /27 in decimal notation?
255.255.255.224
ICANN and IANA
127.0.0.0/8
1

9. What is ICMP Type 9?
Protocols that include subnet masks in their routing updates
Router Advertisement
64
ICMP Router Discovery Protocol

10. Who allocates IP address space and AS numbers to RIRs?
IANA
4
Congestion Window Reduced
Internet Control Message Protocol

11. What TCP/IP protocol suite layer corresponds to the physical and data link layers of the OSI model?
RIRs
Network interface
Reserved (1-bit); DF (1-bit); MF (1-bit)
Router(config-if)#no ip redirects

12. What is the ARP Operation value for an ARP Request?
1
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
Data Offset
Reset

13. What is the maximum length of an IPv4 header?
60 octets
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Internet Service Provider
Padding of zeros to ensure that the header ends on a 32-bit boundary

14. What is prefix /28 in decimal notation?
192.88.99.0/24
255.255.255.240
4
Don't Fragment

15. What is the function of ICMP router advertisement and router selection messages?
1
Used by IRDP on some operating systems to discover local routers
Time Exceeded
9

16. What is the the MF-bit in the IPv4 header?
255.255.255.224
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
More Fragments follow
Internet

17. What is ICMP Type 0?
Congestion Window Reduced
Identifier; Flags and Fragmentation Offset
Echo Reply
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control

18. What is Inverse ARP?

19. What is the ARP Operation value for a Reverse ARP Request?
Each router decrements the TTL
3
Congestion Window Reduced
Host-to-host

20. What is IANA?
RIPv1 and IGRP
255.255.255.252
Largest segment size that the sender is willing to accept
Internet Assigned Numbers Authority

21. What is OSI?
Open Systems Interconnection
Network interface
Router#debug arp
Router Selection

22. Which IPv4 address range is reserved for benchmark testing of Internet devices (RFC 2544)?
198.18.0.0/15
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);
Internet
An ARP request issued by a host with its own IPv4 address as the target address

23. What is ICMP Type 8?
6
Echo
8
Regional Internet Registry

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

25. What is the function of ICMP redirect messages?
Per-Hop Behaviour (PHB)
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Data Offset
Used by routers to notify hosts of another router on the data link that should be used for a particular destination

26. What is the TTL field in the IPv4 header?
Open Systems Interconnection
Sequence Numbers
RIRs
Time to Live

27. What is the recommended default TTL?
An ARP request issued by a host with its own IPv4 address as the target address
64
Router#clear arp-cache [{interface {interface}} | {ip-address}]
IPv4 and IPv6

28. Which protocol has mostly replaced Reverse ARP?
All Internet Registries
Router#debug arp
DHCP
Sequence Numbers

29. Which IPv4 address range is reserved for self-identification on a local subnet?
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
0.0.0.0/8
Router(config)#ip arp proxy disable

30. What is the ARP Operation value for a Reverse ARP Reply?
255.255.255.128
4
Transmission Control Protocol
National Internet Registry

31. What is FIN?
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
DSCP (6-bit); ECN (2-bit)
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Final

32. Deletes dynamic entries from the ARP cache
169.254.0.0/16
Router#clear arp-cache [{interface {interface}} | {ip-address}]
ICANN
Maximum Segment Size (MSS)

33. What is the DF-bit in the IPv4 header?

34. What is SYN?
ICMP Router Discovery Protocol
169.254.0.0/16
4
Synchronize

35. What is the difference between the ToS and the DiffServ byte?
NIRs
They are the same byte - but the names and value interpretations are different
8
127.0.0.0/8

36. What are the IP Precedence values?
89
They are the same byte - but the names and value interpretations are different
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
Windowing

37. What is prefix /25 in decimal notation?
255.255.255.128
Push
Don't Fragment
Local Internet Registry

38. What is ICMP Type 5?
Internet Service Provider
LIRs
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
Redirect

39. What is the format of a TCP header?
Network interface
Used by a host to obtain the IPv4 address associated with its own MAC address
RFC 3330
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

40. Who administers and registers public IP address space and AS numbers within a country or economic unit?
Router Selection
NIRs
Loose source routing; Strict source routing; Record route; Timestamp
2

41. Who owns the processes by which public IP address space and AS numbers are allocated and assigned?
Echo
IPv4 and IPv6
Push
ICANN

42. What is the minimum length of an IPv4 header?
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Network interface
20 octets
0

43. Which IPv4 address range is reserved for use in documentation and example code?
Regional Internet Registry
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
192.0.2.0/24
Synchronize

44. What is CWR?
89
Sequence Numbers
RFC 791
Congestion Window Reduced

45. What are the uses of gratuitous ARP?
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Regional Internet Registry
IANA
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts

46. What is gratuitous ARP?
An ARP request issued by a host with its own IPv4 address as the target address
Internet Assigned Numbers Authority
Redirect
2

47. What is the content of the TCP Window Size field?
Transmission Control Protocol
Router(config-if)#arp timeout {seconds}
2
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

48. What mechanism is used by TCP to provided ordered segment delivery?
Sequence Numbers
They are the same byte - but the names and value interpretations are different
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
Per-Hop Behaviour (PHB)

49. What routing protocols are classful?
Padding of zeros to ensure that the header ends on a 32-bit boundary
RIPv1 and IGRP
89
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)

50. What is the IPv4 Protocol number for TCP?
Both the TCP header and the encapsulated data
Identifier; Flags and Fragmentation Offset
6
National Internet Registry