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IPV4 Addressing

Subject : it-skills

Instructions:

Answer 50 questions in 15 minutes.
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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. Which IPv4 address range is reserved for benchmark testing of Internet devices (RFC 2544)?
Internet Control Message Protocol
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
198.18.0.0/15

2. How does the layers of the TCP/IP protocol suite map to the 7 layers of the OSI model?
Acknowledgement
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
127.0.0.0/8
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured

3. What is the format of the ToS field?
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
Redirect
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application

4. What is ISP?
Internet Service Provider
192.0.2.0/24
Push
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

5. What is the IPv4 Protocol number for IP in IP encapsulation?
4
DHCP
Windowing
Router#debug arp

6. What mechanism is used by TCP to provided ordered segment delivery?
Electrical/Optical - Mechanical - Functional and Procedural
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Sequence Numbers
Router(config-if)#no ip proxy-arp

7. Disables the sending of ICMP redirect messages
Router(config-if)#no ip redirects
DHCP
Time to Live
Echo Reply

8. What is prefix /30 in decimal notation?
Router(config-if)#no ip redirects
All Internet Registries
Time Exceeded
255.255.255.252

9. What mechanisms are used by TCP to provide reliable segment delivery?
Router#debug arp
Acknowledgements - checksums and timers
0
Subtract Header Length field from Total Length field

10. What is the function of ICMP redirect messages?
Padding of zeros to ensure that the header ends on a 32-bit boundary
Internet Corporation for Assigned Network Numbers
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
Synchronize

11. What is prefix /26 in decimal notation?
3
Sequence Number
255.255.255.192
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control

12. What is prefix /25 in decimal notation?
1
Echo Reply
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
255.255.255.128

13. What are classless routing protocols?
Data Offset
Protocols that include subnet masks in their routing updates
IANA
Regional Internet Registry

14. What is RIR?
Time to Live
Open Systems Interconnection
Regional Internet Registry
All Internet Registries

15. Why must the header checksum of an IPv4 packet be recalculated at every router?
Network interface
Uniquely identify every application in the network
Each router decrements the TTL
Host-to-host

16. Which RFC defines the special use IPv4 address ranges?
More Fragments follow
6
Time Exceeded
RFC 3330

17. What TCP/IP protocol suite layer corresponds to the session - presentation and application layers of the OSI model?
Reserved (1-bit); DF (1-bit); MF (1-bit)
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
Application

18. What are the steps to subnet an IPv4 address?
20 octets
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
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
2

19. What is the ARP Protocol type value for IPv4?
0x0800
255.255.255.252
Sequence Number
Transmission Control Protocol

20. What mechanism is used by TCP to regulate the flow of segments?
4
Protocols that include subnet masks in their routing updates
ICANN
Windowing

21. What is prefix /27 in decimal notation?
Reserved (1-bit); DF (1-bit); MF (1-bit)
255.255.255.252
255.255.255.224
0.0.0.0/8

22. Specifies the format in which subnet masks are displayed in show command output
255.255.255.224
National Internet Registry
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
Don't Fragment

23. What is OSI?
Open Systems Interconnection
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
0.0.0.0/8

24. Who can assign IP address space to end user organizations?
Uniquely identify every application in the network
All Internet Registries
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Internet Assigned Numbers Authority

25. What is the ARP Operation value for an ARP Request?
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
1
DHCP
6

26. Which RFC defines the private IPv4 address ranges?
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
ICMP Router Discovery Protocol
RFC 1918
64

27. What is a TCP port number of an application called when it is coupled with the IP address of the server?
Socket
255.255.255.240
1
88

28. What is the ARP Hardware type value for Ethernet?
255.255.255.224
More Fragments follow
Internet Assigned Numbers Authority
1

29. What is the Fragment Offset field in the IPv4 header?
Local Internet Registry
An ARP request issued by a host with its own IPv4 address as the target address
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment

30. What is ICMP Type 11?
Time Exceeded
3
4
National Internet Registry

31. What is the name of the queuing and forwarding of IP packets based on DiffServ?
ICANN
Protocols that don't include subnet masks in their routing updates
4
Per-Hop Behaviour (PHB)

32. Who are LIRs?
89
Mostly large ISPs - enterprises - or academic institutions
169.254.0.0/16
Destination Unreachable

33. What is the recommended default TTL?
National Internet Registry
64
Internet Protocol
IPv4 and IPv6

34. What is the first octet rule for IPv4 address classes in decimal?
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
1
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Reserved (1-bit); DF (1-bit); MF (1-bit)

35. What is ICMP Type 0?
RIRs
Push
255.255.255.192
Echo Reply

36. Who allocates IP address space and AS numbers to RIRs?
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
IANA
Regional Internet Registry
Time to Live

37. What is the content of the the Urgent Pointer field in the TCP header?
1
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
NIRs
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16

38. What are classful routing protocols?

39. Who administers and registers public IP address space and AS numbers within a country or economic unit?
Host-to-host
Internet Corporation for Assigned Network Numbers
RIRs
NIRs

40. What is ICMP Type 5?
89
169.254.0.0/16
Synchronize
Redirect

41. What is Inverse ARP?

42. Who assigns IP address space to its own customers?
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
LIRs
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
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

43. Deletes dynamic entries from the ARP cache
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Used by IRDP on some operating systems to discover local routers
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
Loose source routing; Strict source routing; Record route; Timestamp

44. What is PSH?
Router(config)#ip arp proxy disable
Push
255.255.255.224
Host-to-host

45. Disables proxy ARP on all interfaces
IANA
Router(config-if)#no ip redirects
Router(config)#ip arp proxy disable
255.255.255.224

46. Displays the ARP cache of a router
Router#show arp
Local Internet Registry
ECN-Echo
Push

47. What is the format of a UDP header?
6
Electrical/Optical - Mechanical - Functional and Procedural
Per-Hop Behaviour (PHB)
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)

48. What is the ARP Operation value for an Inverse ARP Request?
17
Internet Service Provider
8
Sequence Number

49. What is the format of an IPv4 header?
RFC 791
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);
IPv4 and IPv6
Router(config-if)#arp timeout {seconds}

50. What is the IPv4 Protocol number for OSPF?
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
89
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
255.255.255.252