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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 ICMP Type 5?
0
Redirect
Echo Reply
2

2. What is ICMP Type 11?
Regional Internet Registry
RIPv1 and IGRP
Time Exceeded
Subtract Header Length field from Total Length field

3. What is IRDP?
IANA
ICMP Router Discovery Protocol
An ARP request issued by a host with its own IPv4 address as the target address
255.255.255.240

4. What is ICMP?
Socket
IPv4 and IPv6
Internet Control Message Protocol
255.255.255.192

5. Which RFC defines the private IPv4 address ranges?
Protocols that include subnet masks in their routing updates
Internet
RFC 1918
Router(config-if)#arp timeout {seconds}

6. What is prefix /28 in decimal notation?
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
Congestion Window Reduced
ICANN and IANA
255.255.255.240

7. What is the IPv4 Protocol number for OSPF?
89
Internet Control Message Protocol
IANA
Windowing

8. Who allocates IP address space and AS numbers to RIRs?
IANA
Acknowledgement
3
Used by routers to notify hosts of another router on the data link that should be used for a particular destination

9. What is URG?
Urgent
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
Both the TCP header and the encapsulated data
DSCP (6-bit); ECN (2-bit)

10. What is the format of a UDP header?
Largest segment size that the sender is willing to accept
Router Selection
Application
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)

11. What is the format of the ToS field?
All Internet Registries
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
Largest segment size that the sender is willing to accept
Network interface

12. What is prefix /29 in decimal notation?
0.0.0.0/8
255.255.255.248
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
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}

13. Which RFC defines IPv4?
IANA
Length of header in words (32-bit)
Internet Corporation for Assigned Network Numbers
RFC 791

14. Why must the header checksum of an IPv4 packet be recalculated at every router?
NIRs
1
Each router decrements the TTL
169.254.0.0/16

15. 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
89
9
6

16. What is the format of a TCP header?
255.255.255.192
Electrical/Optical - Mechanical - Functional and Procedural
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
192.0.2.0/24

17. What routing protocols are classful?
Redirect
Time Exceeded
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
RIPv1 and IGRP

18. What is the difference between the ToS and the DiffServ byte?
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
They are the same byte - but the names and value interpretations are different
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);
Router(config)#ip arp proxy disable

19. What is ICMP Type 10?
Reset
46
192.88.99.0/24
Router Selection

20. Which IPv4 address range is reserved for IPv6 to IPv4 (6to4) relays (RFC 3068)?
192.88.99.0/24
Reserved (1-bit); DF (1-bit); MF (1-bit)
Protocols that don't include subnet masks in their routing updates
Both the TCP header and the encapsulated data

21. What are the private IPv4 address ranges?
Windowing
More Fragments follow
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Internet

22. Who administers and registers IP address space and AS numbers within a region?
Acknowledgements - checksums and timers
ECN-Echo
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
RIRs

23. What is CWR?
Uniquely identify every application in the network
17
LIRs
Congestion Window Reduced

24. What is the format of the ToS byte in the IPv4 header?
RFC 1918
2
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Reserved (1-bit); DF (1-bit); MF (1-bit)

25. What TCP/IP protocol suite layer corresponds to the physical and data link layers of the OSI model?
Network interface
Application
Data Offset
89

26. What is SYN?
Identifier; Flags and Fragmentation Offset
192.0.2.0/24
Internet Service Provider
Synchronize

27. What is the format of the TCP Header Length field?
Length of header in words (32-bit)
Internet Protocol
255.255.255.240
The next sequence number that the source expects to receive from the destination

28. Disables proxy ARP on an interface
Acknowledgements - checksums and timers
IANA
Router(config-if)#no ip proxy-arp
Time Exceeded

29. Disables the sending of ICMP redirect messages
Router#debug arp
Router(config)#ip arp proxy disable
Router(config-if)#no ip redirects
Mostly large ISPs - enterprises - or academic institutions

30. What is PSH?
Electrical/Optical - Mechanical - Functional and Procedural
Push
DHCP
Destination Unreachable

31. What TCP/IP protocol suite layer corresponds to the network layer of the OSI model?
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Internet
IPv4 and IPv6

32. What is FIN?
Final
127.0.0.0/8
Length of header in words (32-bit)
Subtract Header Length field from Total Length field

33. What is the recommended default TTL?
64
2
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
Protocols that don't include subnet masks in their routing updates

34. What is the function of ICMP redirect messages?
Per-Hop Behaviour (PHB)
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
The next sequence number that the source expects to receive from the destination
Internet Corporation for Assigned Network Numbers

35. Who is responsible for maintaining the official assignments of TCP and UDP port numbers for specific uses?
National Internet Registry
Host-to-host
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
IANA

36. What mechanism is used by TCP to provided ordered segment delivery?
Synchronize
6
ECN-Echo
Sequence Numbers

37. What is OSI?
Largest segment size that the sender is willing to accept
Router Selection
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
Open Systems Interconnection

38. What is the IPv4 Protocol number for GRE?
DHCP
They are the same byte - but the names and value interpretations are different
47
ECN-Echo

39. What is added after the Option field in the TCP header?
Padding of zeros to ensure that the header ends on a 32-bit boundary
Internet Assigned Numbers Authority
Push
Both the TCP header and the encapsulated data

40. What is ICMP Type 0?
Echo Reply
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
Congestion Window Reduced
LIRs

41. What is the the MF-bit in the IPv4 header?
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
Sequence Number + Data payload octets + 1
More Fragments follow
Used by a host to obtain the IPv4 address associated with its own MAC address

42. Which RFC defines the special use IPv4 address ranges?
8
Router(config-if)#arp timeout {seconds}
Final
RFC 3330

43. What is the ARP Operation value for a Reverse ARP Reply?
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
6
4
Mostly large ISPs - enterprises - or academic institutions

44. What is the formula to calculate the next Sequence Number based on the Sequence Number of the current TCP segment?
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
169.254.0.0/16
Synchronize
Sequence Number + Data payload octets + 1

45. Who are LIRs?
Acknowledgement
Internet Control Message Protocol
Data Offset
Mostly large ISPs - enterprises - or academic institutions

46. What is the IPv4 Protocol number for IGMP?
The next sequence number that the source expects to receive from the destination
IPv4 and IPv6
2
192.88.99.0/24

47. What is ECE?
Sequence Numbers
4
Each router decrements the TTL
ECN-Echo

48. What field identifies where the TCP encapsulated data fits within the data stream from the sender?
Protocols that include subnet masks in their routing updates
Sequence Number
Router(config)#arp {ip-address} {mac-address} arpa
Destination Unreachable

49. Which IPv4 address range is reserved for loopback testing?
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
255.255.255.128
127.0.0.0/8
192.88.99.0/24

50. What is ICMP Type 3?
17
3
Destination Unreachable
Padding of zeros to ensure that the header ends on a 32-bit boundary