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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 ARP?
255.255.255.248
47
Padding of zeros to ensure that the header ends on a 32-bit boundary
Address Resolution Protocol

2. Which RFC defines the special use IPv4 address ranges?
Transmission Control Protocol
1
RFC 3330
IPv4 and IPv6

3. What is the the MF-bit in the IPv4 header?
LIRs
Sequence Number
Time Exceeded
More Fragments follow

4. What is ECE?
LIRs
Local Internet Registry
ECN-Echo
Echo

5. What is ICANN?
National Internet Registry
Application
Internet Corporation for Assigned Network Numbers
89

6. What is ACK?
The next sequence number that the source expects to receive from the destination
Electrical/Optical - Mechanical - Functional and Procedural
Acknowledgement
Router#debug arp

7. Who owns the processes by which public IP address space and AS numbers are allocated and assigned?
4
Address Resolution Protocol
ICANN
National Internet Registry

8. What is the ARP Operation value for an Inverse ARP Reply?
9
Network interface
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
47

9. What is the format of a TCP header?
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
46
9
Router#clear arp-cache [{interface {interface}} | {ip-address}]

10. What is prefix /25 in decimal notation?
255.255.255.128
Each router decrements the TTL
Router(config)#arp {ip-address} {mac-address} arpa
Per-Hop Behaviour (PHB)

11. Which RFC defines the private IPv4 address ranges?
Internet Assigned Numbers Authority
Mostly large ISPs - enterprises - or academic institutions
RFC 1918
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured

12. What is the content of the TCP Window Size field?
6
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
3
20 octets

13. What is prefix /27 in decimal notation?
Router(config-if)#no ip redirects
255.255.255.224
Router#clear arp-cache [{interface {interface}} | {ip-address}]
ICANN

14. What is the function of ICMP redirect messages?
DSCP (6-bit); ECN (2-bit)
Acknowledgements - checksums and timers
Push
Used by routers to notify hosts of another router on the data link that should be used for a particular destination

15. What mechanism is used by TCP to regulate the flow of segments?
Windowing
Electrical/Optical - Mechanical - Functional and Procedural
DSCP (6-bit); ECN (2-bit)
47

16. What is gratuitous ARP?
Protocols that don't include subnet masks in their routing updates
They are the same byte - but the names and value interpretations are different
Redirect
An ARP request issued by a host with its own IPv4 address as the target address

17. What is the format of the TCP Header Length field?
Loose source routing; Strict source routing; Record route; Timestamp
Length of header in words (32-bit)
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
6

18. What are the uses of gratuitous ARP?
LIRs
Loose source routing; Strict source routing; Record route; Timestamp
Local Internet Registry
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts

19. What is the IPv4 Protocol number for GRE?
Router(config)#ip arp proxy disable
Used by IRDP on some operating systems to discover local routers
47
0.0.0.0/8

20. What is the IPv4 Protocol number for OSPF?
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
IPv4 and IPv6
1
89

21. What are the steps to subnet an IPv4 address?
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
IANA
Loose source routing; Strict source routing; Record route; Timestamp
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)

22. What TCP/IP protocol suite layer corresponds to the network layer of the OSI model?
Internet
Used by a host to obtain the IP address associated with another host's MAC address
Length of header in words (32-bit)
Identifier; Flags and Fragmentation Offset

23. What is added after the option field in the IPv4 header?
Used by a host to obtain the IPv4 address associated with its own MAC address
Internet Control Message Protocol
6
Padding of zeros to ensure that the header ends on a 32-bit boundary

24. What is the value of the TCP Reserved field?
0
Protocols that don't include subnet masks in their routing updates
RFC 1918
Router(config-if)#no ip proxy-arp

25. What is RST?
Destination Unreachable
Reset
IANA
RIRs

26. What is prefix /29 in decimal notation?
They are the same byte - but the names and value interpretations are different
Open Systems Interconnection
255.255.255.248
255.255.255.252

27. Which IPv4 address range is reserved for self-identification on a local subnet?
RIPv1 and IGRP
0.0.0.0/8
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
64

28. What is ICMP Type 5?
Time Exceeded
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
The next sequence number that the source expects to receive from the destination
Redirect

29. Enables debugging output for ARP transactions
Router(config-if)#arp timeout {seconds}
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
Router#debug arp
Destination Unreachable

30. What is FIN?
Final
Sequence Numbers
ICMP Router Discovery Protocol
RIRs

31. What is Reverse ARP?
RIRs
Used by a host to obtain the IPv4 address associated with its own MAC address
Each router decrements the TTL
They are the same byte - but the names and value interpretations are different

32. Why must the header checksum of an IPv4 packet be recalculated at every router?
255.255.255.240
Router(config)#ip arp proxy disable
Router Selection
Each router decrements the TTL

33. What is ICMP Type 3?
Mostly large ISPs - enterprises - or academic institutions
Destination Unreachable
Used by a host to obtain the IP address associated with another host's MAC address
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

34. What is a TCP port number of an application called when it is coupled with the IP address of the server?
Socket
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Reserved (1-bit); DF (1-bit); MF (1-bit)
URG flag set

35. What is the format of the DiffServ byte?
DSCP (6-bit); ECN (2-bit)
RFC 1918
Synchronize
LIRs

36. What is the format of the ToS byte in the IPv4 header?
192.0.2.0/24
Time Exceeded
Reserved (1-bit); DF (1-bit); MF (1-bit)
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)

37. What is ICMP Type 11?
6
Time Exceeded
198.18.0.0/15
4

38. What is the maximum length of an IPv4 header?
60 octets
ECN-Echo
Maximum Segment Size (MSS)
IANA

39. What is prefix /30 in decimal notation?
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
255.255.255.252
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
2

40. What are the most common IP version numbers?
Windowing
RIRs
Router(config)#ip arp proxy disable
IPv4 and IPv6

41. What is the purpose of a socket?
Used by a host to obtain the IPv4 address associated with its own MAC address
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
Uniquely identify every application in the network
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

42. What is IRDP?
88
The next sequence number that the source expects to receive from the destination
ICMP Router Discovery Protocol
127.0.0.0/8

43. What is the IPv4 Protocol number for IP in IP encapsulation?
4
Internet Protocol
Router(config)#arp {ip-address} {mac-address} arpa
Padding of zeros to ensure that the header ends on a 32-bit boundary

44. What is the difference between the ToS and the DiffServ byte?
Length of header in words (32-bit)
Router(config-if)#no ip proxy-arp
They are the same byte - but the names and value interpretations are different
RFC 791

45. Who assigns IP address space to its own customers?
Internet Protocol
LIRs
Router(config-if)#no ip redirects
RFC 1918

46. What is ICMP Type 8?
Router(config-if)#arp timeout {seconds}
Echo
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
DHCP

47. Who is responsible for maintaining the official assignments of TCP and UDP port numbers for specific uses?
Router#show arp
IANA
RFC 3330
IPv4 and IPv6

48. What is the name of the queuing and forwarding of IP packets based on DiffServ?
Length of header in words (32-bit)
Per-Hop Behaviour (PHB)
RFC 791
64

49. What is SYN?
Router(config)#arp {ip-address} {mac-address} arpa
Internet Protocol
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
Synchronize

50. What is the ARP Operation value for a Reverse ARP Reply?
4
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
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}