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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. What is prefix /30 in decimal notation?
255.255.255.252
64
RFC 791
URG flag set

2. What IPv4 header fields are used for fragmentation?
The next sequence number that the source expects to receive from the destination
RFC 1918
Sequence Numbers
Identifier; Flags and Fragmentation Offset

3. What is the IPv4 Protocol number for EIGRP?
88
Internet
Length of header in words (32-bit)
Subtract Header Length field from Total Length field

4. What is ICMP?
Internet Control Message Protocol
Used by a host to obtain the IPv4 address associated with its own MAC address
National Internet Registry
0.0.0.0/8

5. What is the IPv4 Protocol number for OSPF?
89
ICANN and IANA
Internet Corporation for Assigned Network Numbers
255.255.255.240

6. What is the IPv4 Protocol number for ICMP?
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
1
DHCP
Internet Protocol

7. What is the content of the TCP Window Size field?
4
Application
IANA
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

8. What is RIR?
Router#show arp
More Fragments follow
Congestion Window Reduced
Regional Internet Registry

9. What is ICMP Type 10?
Router Selection
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
4
LIRs

10. What are the IP Precedence values?
Router Selection
Network interface
ICANN
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control

11. What is the IPv4 Protocol number for IGMP?
8
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
2
Internet Corporation for Assigned Network Numbers

12. Which RFC defines the special use IPv4 address ranges?
Subtract Header Length field from Total Length field
Congestion Window Reduced
169.254.0.0/16
RFC 3330

13. What is a TCP Acknowledgement Number?
The next sequence number that the source expects to receive from the destination
Sequence Numbers
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
Push

14. What is SYN?
Router#show arp
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Synchronize
Internet

15. What is the minimum length of an IPv4 header?
64
20 octets
NIRs
IPv4 and IPv6

16. What is the prerequisite for using the Urgent Pointer field in the TCP header?
URG flag set
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
60 octets
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

17. What are classless routing protocols?
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
Transmission Control Protocol
RFC 791
Protocols that include subnet masks in their routing updates

18. Which IPv4 address range is reserved for loopback testing?
127.0.0.0/8
All Internet Registries
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
RIPv1 and IGRP

19. What mechanism is used by TCP to regulate the flow of segments?
Transmission Control Protocol
Maximum Segment Size (MSS)
Windowing
Internet Corporation for Assigned Network Numbers

20. What are the most common IP version numbers?
Don't Fragment
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
URG flag set
IPv4 and IPv6

21. What is the content of the the Urgent Pointer field in the TCP header?
17
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Open Systems Interconnection
All Internet Registries

22. What are the uses of gratuitous ARP?
ECN-Echo
Protocols that include subnet masks in their routing updates
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
ICANN

23. What is the format of the Flags field in the TCP header?
46
Internet Control Message Protocol
Internet Assigned Numbers Authority
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)

24. What is the content of the Maximum Segment Size (MSS) in the Option field of the TCP header?
Acknowledgement
Largest segment size that the sender is willing to accept
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Uniquely identify every application in the network

25. Adds a permanent static ARP entry for an Ethernet host
Time Exceeded
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
Router(config-if)#no ip proxy-arp
Router(config)#arp {ip-address} {mac-address} arpa

26. Who group public IPv4 address space by major geographic region?
Length of header in words (32-bit)
Urgent
ICANN and IANA
Subtract Header Length field from Total Length field

27. What is ICMP Type 9?
RFC 1918
More Fragments follow
Internet Protocol
Router Advertisement

28. What is the ARP Operation value for an ARP Request?
198.18.0.0/15
255.255.255.224
Internet
1

29. What is proxy ARP?
Acknowledgement
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts

30. Why must the header checksum of an IPv4 packet be recalculated at every router?
DHCP
1
Acknowledgements - checksums and timers
Each router decrements the TTL

31. What is the first octet rule for IPv4 address classes in decimal?
169.254.0.0/16
ICANN and IANA
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Network interface

32. What TCP/IP protocol suite layer corresponds to the physical and data link layers of the OSI model?
Router(config)#ip arp proxy disable
Network interface
IPv4 and IPv6
Both the TCP header and the encapsulated data

33. Which IPv4 address range is reserved for IPv6 to IPv4 (6to4) relays (RFC 3068)?
More Fragments follow
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
All Internet Registries
192.88.99.0/24

34. Who administers and registers public IP address space and AS numbers within a country or economic unit?
Echo Reply
255.255.255.240
NIRs
0.0.0.0/8

35. What is a TCP port number of an application called when it is coupled with the IP address of the server?
Socket
Both the TCP header and the encapsulated data
255.255.255.248
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16

36. What is the name of the queuing and forwarding of IP packets based on DiffServ?
1
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
Per-Hop Behaviour (PHB)
Internet Control Message Protocol

37. What is prefix /26 in decimal notation?
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
3
255.255.255.192
Router(config-if)#arp timeout {seconds}

38. What is the IPv4 Protocol number for IP in IP encapsulation?
1
Per-Hop Behaviour (PHB)
Used by a host to obtain the IP address associated with another host's MAC address
4

39. What is the ARP Operation value for an Inverse ARP Request?
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
Windowing
NIRs
8

40. What is the ARP Operation value for an ARP Reply?
Reset
All Internet Registries
2
Time to Live

41. Who are LIRs?
Mostly large ISPs - enterprises - or academic institutions
64
ICMP Router Discovery Protocol
Per-Hop Behaviour (PHB)

42. What TCP/IP protocol suite layer corresponds to the network layer of the OSI model?
Internet
88
Router(config-if)#arp timeout {seconds}
255.255.255.128

43. What is the format of a UDP header?
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Used by a host to obtain the IP address associated with another host's MAC address
Router(config-if)#no ip proxy-arp
127.0.0.0/8

44. What is FIN?
Final
Sequence Numbers
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Host-to-host

45. Which RFC defines IPv4?
Regional Internet Registry
RFC 791
Router(config-if)#arp timeout {seconds}
Length of header in words (32-bit)

46. What mechanism is used by TCP to provided ordered segment delivery?
Sequence Numbers
Socket
17
255.255.255.248

47. What is the most commonly used Option field in the TCP header?
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
Maximum Segment Size (MSS)
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
Protocols that don't include subnet masks in their routing updates

48. What is the ARP Hardware type value for Ethernet?
Redirect
Final
1
More Fragments follow

49. Which protocol has mostly replaced Reverse ARP?
RFC 1918
4
Padding of zeros to ensure that the header ends on a 32-bit boundary
DHCP

50. What is the format of the Flags field in the IPv4 header?
Reserved (1-bit); DF (1-bit); MF (1-bit)
Each router decrements the TTL
Electrical/Optical - Mechanical - Functional and Procedural
Destination Unreachable