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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 TCP/IP protocol suite layer corresponds to the transport layer of the OSI model?
20 octets
Push
Acknowledgement
Host-to-host

2. What is the ARP Operation value for an Inverse ARP Reply?
Uniquely identify every application in the network
Internet
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
9

3. What is the ARP Operation value for a Reverse ARP Request?
Destination Unreachable
Network interface
3
ICANN and IANA

4. What TCP/IP protocol suite layer corresponds to the session - presentation and application layers of the OSI model?
DSCP (6-bit); ECN (2-bit)
The next sequence number that the source expects to receive from the destination
They are the same byte - but the names and value interpretations are different
Application

5. What is ICANN?
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Length of header in words (32-bit)
192.0.2.0/24
Internet Corporation for Assigned Network Numbers

6. Which protocol has mostly replaced Reverse ARP?
255.255.255.128
1
NIRs
DHCP

7. What is ICMP Type 10?
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Redirect
Router Selection
The next sequence number that the source expects to receive from the destination

8. Enables debugging output for ARP transactions
Router#debug arp
Protocols that don't include subnet masks in their routing updates
Regional Internet Registry
2

9. What field identifies where the TCP encapsulated data fits within the data stream from the sender?
RIRs
Sequence Number
2
Protocols that include subnet masks in their routing updates

10. Disables proxy ARP on all interfaces
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
Router(config)#ip arp proxy disable
IANA
Identifier; Flags and Fragmentation Offset

11. What is the format of an ICMP header?
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
255.255.255.252
6
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields

12. What is the format of a UDP header?
URG flag set
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Redirect

13. What is the ARP Operation value for an ARP Reply?
Transmission Control Protocol
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
2
Push

14. Which RFC defines the private IPv4 address ranges?
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
Router#debug arp
Router(config-if)#arp timeout {seconds}

15. What is ICMP Type 11?
Local Internet Registry
192.0.2.0/24
Time Exceeded
URG flag set

16. What is the IPv4 Protocol number for ICMP?
Internet Assigned Numbers Authority
1
127.0.0.0/8
Host-to-host

17. How does the layers of the TCP/IP protocol suite map to the 7 layers of the OSI model?
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
89
Uniquely identify every application in the network

18. What mechanisms are used by TCP to provide reliable segment delivery?
Destination Unreachable
Acknowledgements - checksums and timers
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Local Internet Registry

19. What is the format of an IPv4 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);
Padding of zeros to ensure that the header ends on a 32-bit boundary
0.0.0.0/8
Largest segment size that the sender is willing to accept

20. What is the TTL field in the IPv4 header?
Open Systems Interconnection
Time to Live
Router Advertisement
9

21. Displays the ARP cache of a router
255.255.255.248
Router#show arp
Local Internet Registry
20 octets

22. What is the ARP Protocol address length value for IPv4?
20 octets
They are the same byte - but the names and value interpretations are different
4
Redirect

23. What is the prerequisite for using the Urgent Pointer field in the TCP header?
17
URG flag set
Open Systems Interconnection
Windowing

24. What is the name of the queuing and forwarding of IP packets based on DiffServ?
Length of header in words (32-bit)
ICANN and IANA
Per-Hop Behaviour (PHB)
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)

25. Disables proxy ARP on an interface
6
0x0800
Protocols that don't include subnet masks in their routing updates
Router(config-if)#no ip proxy-arp

26. What is the ARP Hardware type value for Ethernet?
Padding of zeros to ensure that the header ends on a 32-bit boundary
Used by IRDP on some operating systems to discover local routers
The next sequence number that the source expects to receive from the destination
1

27. Specifies the format in which subnet masks are displayed in show command output
Windowing
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
Echo

28. What is IRDP?
ICMP Router Discovery Protocol
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
RIRs
URG flag set

29. What is the other name for the TCP Header Length field?
ICANN and IANA
NIRs
Reserved (1-bit); DF (1-bit); MF (1-bit)
Data Offset

30. What is the format of a TCP header?
Maximum Segment Size (MSS)
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
Protocols that include subnet masks in their routing updates
Internet

31. 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
17
Per-Hop Behaviour (PHB)
Number of octets to be added to the Sequence Number to indicate the end of the urgent data

32. What is a TCP Acknowledgement Number?
The next sequence number that the source expects to receive from the destination
Subtract Header Length field from Total Length field
Sequence Numbers
Final

33. What is the format of the Flags field in the TCP header?
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
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)
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts

34. What is the format of the DiffServ byte?
IANA
DSCP (6-bit); ECN (2-bit)
2
Push

35. What is the IPv4 Protocol number for IP in IP encapsulation?
Router Advertisement
Subtract Header Length field from Total Length field
Congestion Window Reduced
4

36. What is the IPv4 protocol number for UDP?
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
17
RFC 791
Maximum Segment Size (MSS)

37. What is the IPv4 Protocol number of RSVP?
Sequence Number
ECN-Echo
46
ICMP Router Discovery Protocol

38. How can the receiver determine the size of a packet's data payload based on the IPv4 header?
Subtract Header Length field from Total Length field
169.254.0.0/16
Echo
6

39. What are the uses of gratuitous ARP?
Padding of zeros to ensure that the header ends on a 32-bit boundary
ICANN and IANA
0
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts

40. 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
DSCP (6-bit); ECN (2-bit)
Don't Fragment
Synchronize

41. What is a TCP port number of an application called when it is coupled with the IP address of the server?
Socket
Sequence Numbers
1
Router(config-if)#no ip proxy-arp

42. What is the most commonly used Option field in the TCP header?
Maximum Segment Size (MSS)
Identifier; Flags and Fragmentation Offset
Sequence Number + Data payload octets + 1
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16

43. What is the value of the TCP Reserved field?
Internet Control Message Protocol
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
0
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields

44. Which IPv4 address range is reserved for link-local addresses when DHCP fails?
URG flag set
192.88.99.0/24
17
169.254.0.0/16

45. What is prefix /28 in decimal notation?
9
Transmission Control Protocol
Protocols that include subnet masks in their routing updates
255.255.255.240

46. What is the formula to calculate the next Sequence Number based on the Sequence Number of the current TCP segment?
Time to Live
Electrical/Optical - Mechanical - Functional and Procedural
Sequence Number + Data payload octets + 1
Final

47. What is prefix /26 in decimal notation?
255.255.255.192
Transmission Control Protocol
20 octets
Used by a host to obtain the IP address associated with another host's MAC address

48. What is OSI?
Application
Maximum Segment Size (MSS)
Open Systems Interconnection
4

49. What is covered by the TCP Checksum field?
Maximum Segment Size (MSS)
Router#show arp
Both the TCP header and the encapsulated data
Router#debug arp

50. What is CWR?
198.18.0.0/15
RIPv1 and IGRP
Congestion Window Reduced
RIRs