IPV4 Addressing

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 format of the ToS field?
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
ICMP Router Discovery Protocol
More Fragments follow


2. Disables the sending of ICMP redirect messages
Router(config-if)#no ip redirects
Redirect
Protocols that don't include subnet masks in their routing updates
Internet


3. Which RFC defines the special use IPv4 address ranges?
Identifier; Flags and Fragmentation Offset
RFC 3330
ICANN
Padding of zeros to ensure that the header ends on a 32-bit boundary


4. What is the format of an IPv4 header?
Acknowledgements - checksums and timers
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);
Congestion Window Reduced
64


5. What is prefix /28 in decimal notation?
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Internet Assigned Numbers Authority
Padding of zeros to ensure that the header ends on a 32-bit boundary
255.255.255.240


6. What is the format of an ARP packet?
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
NIRs
Socket
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


7. Deletes dynamic entries from the ARP cache
Router#clear arp-cache [{interface {interface}} | {ip-address}]
National Internet Registry
Uniquely identify every application in the network
LIRs


8. What is the IPv4 Protocol number of RSVP?
Router Advertisement
46
6
RFC 3330


9. Configures how long a dynamically learned protocol address and its corresponding hardware address remains in the ARP cache
Router(config-if)#arp timeout {seconds}
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
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
RIRs


10. What is ICMP Type 9?
Router Advertisement
Used by a host to obtain the IPv4 address associated with its own MAC address
9
Time to Live


11. What is covered by the TCP Checksum field?
Internet Protocol
URG flag set
Both the TCP header and the encapsulated data
NIRs


12. What is the IPv4 Protocol number for IGMP?
Sequence Number
2
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
0x0800


13. What is Inverse ARP?


14. What is the IPv4 Protocol number for EIGRP?
88
Router#clear arp-cache [{interface {interface}} | {ip-address}]
ICANN
Redirect


15. What is ICMP Type 3?
4
Transmission Control Protocol
Address Resolution Protocol
Destination Unreachable


16. What is NIR?
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);
National Internet Registry
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
Padding of zeros to ensure that the header ends on a 32-bit boundary


17. Which RFC defines the private IPv4 address ranges?
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
RFC 1918
89
1


18. What is the value of the TCP Reserved field?
0
Local Internet Registry
0x0800
Echo


19. What mechanism is used by TCP to provided ordered segment delivery?
Sequence Numbers
Network interface
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254


20. Why must the header checksum of an IPv4 packet be recalculated at every router?
Time Exceeded
Internet Corporation for Assigned Network Numbers
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Each router decrements the TTL


21. What is the ARP Hardware address length value for Ethernet?
Router Selection
4
60 octets
6


22. What is IP?
Largest segment size that the sender is willing to accept
Internet Protocol
Host-to-host
Length of header in words (32-bit)


23. What is the DF-bit in the IPv4 header?


24. What is the other name for the TCP Header Length field?
Data Offset
Padding of zeros to ensure that the header ends on a 32-bit boundary
89
Redirect


25. What is ECE?
Length of header in words (32-bit)
ECN-Echo
46
Subtract Header Length field from Total Length field


26. What TCP/IP protocol suite layer corresponds to the transport layer of the OSI model?
6
Host-to-host
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


27. What are the most common IP version numbers?
255.255.255.192
Socket
IPv4 and IPv6
Address Resolution Protocol


28. What is the IPv4 Protocol number for IP in IP encapsulation?
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
4
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
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111


29. What is the format of the DiffServ byte?
Router#debug arp
88
4
DSCP (6-bit); ECN (2-bit)


30. Specifies the format in which subnet masks are displayed in show command output
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
IANA
Destination Unreachable


31. What is the TTL field in the IPv4 header?
Time to Live
Network interface
255.255.255.192
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)


32. What is the format of a TCP header?
Identifier; Flags and Fragmentation Offset
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
Each router decrements the TTL
Router Advertisement


33. What is SYN?
89
IANA
Synchronize
Echo


34. What is the purpose of a socket?
Uniquely identify every application in the network
RIRs
LIRs
Internet


35. What are the steps to subnet an IPv4 address?
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Sequence Numbers
169.254.0.0/16
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


36. What IPv4 header fields are used for fragmentation?
Identifier; Flags and Fragmentation Offset
Time Exceeded
Acknowledgements - checksums and timers
Padding of zeros to ensure that the header ends on a 32-bit boundary


37. Who are LIRs?
255.255.255.128
Windowing
Internet
Mostly large ISPs - enterprises - or academic institutions


38. Which IPv4 address range is reserved for use in documentation and example code?
192.0.2.0/24
9
Reserved (1-bit); DF (1-bit); MF (1-bit)
Host-to-host


39. What is gratuitous ARP?
255.255.255.192
An ARP request issued by a host with its own IPv4 address as the target address
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);
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16


40. What is the content of the the Urgent Pointer field in the TCP header?
Padding of zeros to ensure that the header ends on a 32-bit boundary
LIRs
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
4


41. What is ACK?
ICMP Router Discovery Protocol
Acknowledgement
Each router decrements the TTL
Local Internet Registry


42. What is RIR?
9
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Regional Internet Registry
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16


43. Who administers and registers IP address space and AS numbers within a region?
RIRs
Destination Unreachable
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
9


44. What is the prerequisite for using the Urgent Pointer field in the TCP header?
URG flag set
RIPv1 and IGRP
64
Uniquely identify every application in the network


45. What TCP/IP protocol suite layer corresponds to the session - presentation and application layers of the OSI model?
Final
Application
Router(config)#arp {ip-address} {mac-address} arpa
An ARP request issued by a host with its own IPv4 address as the target address


46. What is the formula to calculate the next Sequence Number based on the Sequence Number of the current TCP segment?
0
Echo
Sequence Number + Data payload octets + 1
Subtract Header Length field from Total Length field


47. What is the ARP Hardware type value for Ethernet?
1
192.88.99.0/24
4
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


48. What is ICMP Type 11?
They are the same byte - but the names and value interpretations are different
NIRs
Time to Live
Time Exceeded


49. What is the format of the TCP Header Length field?
Padding of zeros to ensure that the header ends on a 32-bit boundary
Uniquely identify every application in the network
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);
Length of header in words (32-bit)


50. What is ARP?
IANA
Open Systems Interconnection
Mostly large ISPs - enterprises - or academic institutions
Address Resolution Protocol