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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 ARP Operation value for a Reverse ARP Request?
3
RFC 1918
Data Offset
127.0.0.0/8

2. Why must the header checksum of an IPv4 packet be recalculated at every router?
Router(config)#arp {ip-address} {mac-address} arpa
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
Each router decrements the TTL
255.255.255.248

3. What is the IPv4 Protocol number for EIGRP?
Open Systems Interconnection
Router Advertisement
88
Protocols that don't include subnet masks in their routing updates

4. Which protocol has mostly replaced Reverse ARP?
Time Exceeded
DHCP
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
Address Resolution Protocol

5. Who owns the processes by which public IP address space and AS numbers are allocated and assigned?
ICANN
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
2
Identifier; Flags and Fragmentation Offset

6. What is a TCP Acknowledgement Number?
20 octets
1
The next sequence number that the source expects to receive from the destination
192.0.2.0/24

7. What is LIR?
IANA
Local Internet Registry
Subtract Header Length field from Total Length field
1

8. What is TCP?
Router(config-if)#arp timeout {seconds}
Transmission Control Protocol
Acknowledgements - checksums and timers
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

9. Disables the sending of ICMP redirect messages
Router(config-if)#no ip redirects
6
Urgent
255.255.255.248

10. What is PSH?
Each router decrements the TTL
1
8
Push

11. What is ISP?
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Internet Service Provider
192.0.2.0/24

12. What is the format of an ICMP header?
192.0.2.0/24
LIRs
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
Padding of zeros to ensure that the header ends on a 32-bit boundary

13. What is the ARP Operation value for an ARP Reply?
2
Router Advertisement
Synchronize
Used by routers to notify hosts of another router on the data link that should be used for a particular destination

14. What is the first octet rule for IPv4 address classes in binary?
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
Mostly large ISPs - enterprises - or academic institutions
Redirect

15. What is the format of the ToS field?
Final
Internet Corporation for Assigned Network Numbers
Router(config)#arp {ip-address} {mac-address} arpa
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)

16. What mechanism is used by TCP to provided ordered segment delivery?
2
Sequence Numbers
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
RIRs

17. What is Reverse ARP?
192.0.2.0/24
Data Offset
169.254.0.0/16
Used by a host to obtain the IPv4 address associated with its own MAC address

18. What is the format of an ARP packet?
127.0.0.0/8
Acknowledgements - checksums and timers
4
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

19. What is the ARP Operation value for an ARP Request?
47
0.0.0.0/8
198.18.0.0/15
1

20. Which RFC defines the private IPv4 address ranges?
Internet Assigned Numbers Authority
RFC 1918
169.254.0.0/16
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields

21. What are classless routing protocols?
Host-to-host
Protocols that include subnet masks in their routing updates
255.255.255.240
Time Exceeded

22. What is the minimum length of an IPv4 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
Time to Live
Sequence Number + Data payload octets + 1
20 octets

23. What is proxy ARP?
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
198.18.0.0/15
RIPv1 and IGRP

24. What is IRDP?
Router Advertisement
Router#debug arp
ICMP Router Discovery Protocol
Used by IRDP on some operating systems to discover local routers

25. What is the IPv4 Protocol number for OSPF?
89
Maximum Segment Size (MSS)
Router(config-if)#no ip proxy-arp
IANA

26. What are the private IPv4 address ranges?
4
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
ICANN
DSCP (6-bit); ECN (2-bit)

27. Enables debugging output for ARP transactions
ICANN and IANA
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
Router#debug arp
They are the same byte - but the names and value interpretations are different

28. What is the value of the TCP Reserved field?
Data Offset
Windowing
Reserved (1-bit); DF (1-bit); MF (1-bit)
0

29. Who is responsible for the global coordination of the DNS Root - IP addressing - and other Internet protocol resources?
IANA
Application
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)

30. Configures how long a dynamically learned protocol address and its corresponding hardware address remains in the ARP cache
IANA
6
88
Router(config-if)#arp timeout {seconds}

31. What is IP?
ICANN
Internet Protocol
6
88

32. What is the the MF-bit in the IPv4 header?
Mostly large ISPs - enterprises - or academic institutions
4
Router Advertisement
More Fragments follow

33. Who is responsible for maintaining the official assignments of TCP and UDP port numbers for specific uses?
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
198.18.0.0/15
IANA
ICMP Router Discovery Protocol

34. What TCP/IP protocol suite layer corresponds to the transport layer of the OSI model?
Data Offset
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Host-to-host
National Internet Registry

35. What is ICANN?
Electrical/Optical - Mechanical - Functional and Procedural
88
Internet Corporation for Assigned Network Numbers
0.0.0.0/8

36. Which RFC defines the special use IPv4 address ranges?
RIRs
255.255.255.192
RFC 3330
0.0.0.0/8

37. 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
Redirect
Time to Live
Subtract Header Length field from Total Length field

38. What is the ARP Protocol type value for IPv4?
0x0800
URG flag set
0.0.0.0/8
Electrical/Optical - Mechanical - Functional and Procedural

39. Who allocates IP address space and AS numbers to RIRs?
1
88
IANA
Final

40. What is CWR?
Push
Used by a host to obtain the IPv4 address associated with its own MAC address
Congestion Window Reduced
They are the same byte - but the names and value interpretations are different

41. What are the most common IP version numbers?
Destination Unreachable
Internet Control Message Protocol
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
IPv4 and IPv6

42. What is the IPv4 Protocol number for GRE?
RIRs
47
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);
Protocols that include subnet masks in their routing updates

43. What is RST?
Sequence Number + Data payload octets + 1
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
47
Reset

44. What is the purpose of a socket?
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
IPv4 and IPv6
Uniquely identify every application in the network
Push

45. What is the most commonly used Option field in the TCP header?
Echo Reply
Maximum Segment Size (MSS)
Time Exceeded
Push

46. Who administers and registers public IP address space and AS numbers within a country or economic unit?
NIRs
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control

47. What is SYN?
Time to Live
Synchronize
Internet Control Message Protocol
RIPv1 and IGRP

48. What is ACK?
Acknowledgement
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
Reserved (1-bit); DF (1-bit); MF (1-bit)
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

49. How can the receiver determine the size of a packet's data payload based on the IPv4 header?
DHCP
Subtract Header Length field from Total Length field
They are the same byte - but the names and value interpretations are different
Reset

50. What field identifies where the TCP encapsulated data fits within the data stream from the sender?
RFC 3330
Sequence Number
169.254.0.0/16
Time to Live