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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 content of the the Urgent Pointer field in the TCP header?
Largest segment size that the sender is willing to accept
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
127.0.0.0/8
Don't Fragment

2. What is the format of an ARP packet?
An ARP request issued by a host with its own IPv4 address as the target address
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
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);
Used by a host to obtain the IP address associated with another host's MAC address

3. What is a TCP port number of an application called when it is coupled with the IP address of the server?
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Socket
Congestion Window Reduced
127.0.0.0/8

4. Who group public IPv4 address space by major geographic region?
Protocols that don't include subnet masks in their routing updates
ICANN and IANA
4
Transmission Control Protocol

5. Who administers and registers IP address space and AS numbers within a region?
RIRs
Router#clear arp-cache [{interface {interface}} | {ip-address}]
17
Per-Hop Behaviour (PHB)

6. What is the recommended default TTL?
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
4
47
64

7. What is ECE?
Protocols that don't include subnet masks in their routing updates
RFC 1918
17
ECN-Echo

8. What is LIR?
255.255.255.240
Local Internet Registry
Uniquely identify every application in the network
Application

9. What is ARP?
Address Resolution Protocol
Push
Mostly large ISPs - enterprises - or academic institutions
Router(config-if)#arp timeout {seconds}

10. Who allocates IP address space and AS numbers to RIRs?
198.18.0.0/15
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
IANA
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

11. What is the IPv4 Protocol number for ICMP?
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
Internet Service Provider
1
Each router decrements the TTL

12. What is the IPv4 Protocol number for IP in IP encapsulation?
8
ECN-Echo
Reset
4

13. What is the maximum length of an IPv4 header?
Router#debug arp
60 octets
Electrical/Optical - Mechanical - Functional and Procedural
Protocols that include subnet masks in their routing updates

14. Who are LIRs?
Internet
Padding of zeros to ensure that the header ends on a 32-bit boundary
Mostly large ISPs - enterprises - or academic institutions
Host-to-host

15. What is the first octet rule for IPv4 address classes in binary?
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
RFC 1918
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111

16. Disables proxy ARP on an interface
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
They are the same byte - but the names and value interpretations are different
Congestion Window Reduced
Router(config-if)#no ip proxy-arp

17. Which IPv4 address range is reserved for use in documentation and example code?
47
192.88.99.0/24
Maximum Segment Size (MSS)
192.0.2.0/24

18. What is TCP?
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
0x0800
Transmission Control Protocol

19. What routing protocols are classful?
RIPv1 and IGRP
Length of header in words (32-bit)
1
0x0800

20. What IPv4 header fields are used for fragmentation?
DSCP (6-bit); ECN (2-bit)
Redirect
Identifier; Flags and Fragmentation Offset
3

21. What is the most commonly used Option field in the TCP header?
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);
Maximum Segment Size (MSS)
1
Acknowledgements - checksums and timers

22. What is the format of the ToS field?
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
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);
127.0.0.0/8
RIPv1 and IGRP

23. What is the other name for the TCP Header Length field?
Data Offset
192.88.99.0/24
Synchronize
Router(config)#arp {ip-address} {mac-address} arpa

24. What is Reverse ARP?
Sequence Number + Data payload octets + 1
169.254.0.0/16
RIRs
Used by a host to obtain the IPv4 address associated with its own MAC address

25. What is a TCP Acknowledgement Number?
Internet Control Message Protocol
Acknowledgements - checksums and timers
ICMP Router Discovery Protocol
The next sequence number that the source expects to receive from the destination

26. What is the first octet rule for IPv4 address classes in decimal?
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
88
2
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)

27. How does the layers of the TCP/IP protocol suite map to the 7 layers of the OSI model?
Destination Unreachable
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
Router(config-if)#no ip proxy-arp
192.88.99.0/24

28. What is the ARP Protocol address length value for IPv4?
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
4
Sequence Number + Data payload octets + 1
Router#clear arp-cache [{interface {interface}} | {ip-address}]

29. What is gratuitous ARP?
0x0800
An ARP request issued by a host with its own IPv4 address as the target address
Subtract Header Length field from Total Length field
RIRs

30. What is ISP?
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
Socket
Internet Service Provider
255.255.255.252

31. What is the format of a TCP header?
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
More Fragments follow
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
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

32. What is the format of the TCP Header Length field?
Open Systems Interconnection
Length of header in words (32-bit)
More Fragments follow
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

33. What is ICMP Type 11?
255.255.255.192
Time Exceeded
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);

34. What is PSH?
RFC 3330
Push
NIRs
Socket

35. What are the steps to subnet an IPv4 address?
RIPv1 and IGRP
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
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
4

36. Who owns the processes by which public IP address space and AS numbers are allocated and assigned?
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
0x0800
ICANN
Time Exceeded

37. What is prefix /30 in decimal notation?
Both the TCP header and the encapsulated data
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);
255.255.255.252
4

38. What is the IPv4 Protocol number for IGMP?
4
Padding of zeros to ensure that the header ends on a 32-bit boundary
More Fragments follow
2

39. Which RFC defines the special use IPv4 address ranges?
RFC 3330
Network interface
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111

40. Who assigns IP address space to its own customers?
Data Offset
RFC 1918
LIRs
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

41. What is the ARP Protocol type value for IPv4?
Synchronize
Open Systems Interconnection
0x0800
All Internet Registries

42. What is FIN?
Reserved (1-bit); DF (1-bit); MF (1-bit)
Regional Internet Registry
Local Internet Registry
Final

43. What is the ARP Operation value for an ARP Request?
3
Router(config-if)#arp timeout {seconds}
1
They are the same byte - but the names and value interpretations are different

44. What is the IPv4 Protocol number for OSPF?
Used by a host to obtain the IPv4 address associated with its own MAC address
89
255.255.255.224
2

45. What is OSI?
20 octets
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Open Systems Interconnection
47

46. What is covered by the TCP Checksum field?
Router#clear arp-cache [{interface {interface}} | {ip-address}]
0
Both the TCP header and the encapsulated data
Sequence Numbers

47. What is added after the Option field in the TCP header?
169.254.0.0/16
Mostly large ISPs - enterprises - or academic institutions
Padding of zeros to ensure that the header ends on a 32-bit boundary
Time Exceeded

48. Who can assign IP address space to end user organizations?
All Internet Registries
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
Each router decrements the TTL
More Fragments follow

49. What are the uses of gratuitous ARP?
8
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
URG flag set
Data Offset

50. What is the function of ICMP redirect messages?
1
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
Acknowledgements - checksums and timers