Test your basic knowledge |

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 Inverse ARP?

2. What is the purpose of a socket?
Each router decrements the TTL
Uniquely identify every application in the network
Address Resolution Protocol
89

3. What is the minimum length of an IPv4 header?
20 octets
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
Regional Internet Registry
Maximum Segment Size (MSS)

4. Configures how long a dynamically learned protocol address and its corresponding hardware address remains in the ARP cache
Router(config-if)#arp timeout {seconds}
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
Sequence Number
Acknowledgements - checksums and timers

5. What is the ARP Operation value for an Inverse ARP Reply?
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
9
Destination Unreachable

6. What TCP/IP protocol suite layer corresponds to the network layer of the OSI model?
255.255.255.240
Internet
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16

7. What are classless routing protocols?
RFC 3330
Internet Control Message Protocol
Protocols that include subnet masks in their routing updates
Congestion Window Reduced

8. What is ICANN?
Largest segment size that the sender is willing to accept
Both the TCP header and the encapsulated data
Subtract Header Length field from Total Length field
Internet Corporation for Assigned Network Numbers

9. What is the ARP Protocol address length value for IPv4?
Per-Hop Behaviour (PHB)
Internet Service Provider
More Fragments follow
4

10. Which IPv4 address range is reserved for benchmark testing of Internet devices (RFC 2544)?
198.18.0.0/15
3
Acknowledgement
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields

11. Which protocol has mostly replaced Reverse ARP?
DHCP
Subtract Header Length field from Total Length field
8
National Internet Registry

12. What is the format of the ToS byte in the IPv4 header?
198.18.0.0/15
8
89
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)

13. What is RST?
Time Exceeded
Reset
60 octets
Sequence Numbers

14. Which IPv4 address range is reserved for loopback testing?
Internet Service Provider
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
255.255.255.192
127.0.0.0/8

15. What is ICMP Type 11?
Padding of zeros to ensure that the header ends on a 32-bit boundary
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Internet Corporation for Assigned Network Numbers
Time Exceeded

16. What TCP/IP protocol suite layer corresponds to the session - presentation and application layers of the OSI model?
Reset
More Fragments follow
47
Application

17. Disables proxy ARP on an interface
Electrical/Optical - Mechanical - Functional and Procedural
URG flag set
NIRs
Router(config-if)#no ip proxy-arp

18. What TCP/IP protocol suite layer corresponds to the physical and data link layers of the OSI model?
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
RIRs
0x0800
Network interface

19. Disables proxy ARP on all interfaces
Router(config)#ip arp proxy disable
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
6
255.255.255.224

20. What is ACK?
Host-to-host
RIRs
LIRs
Acknowledgement

21. What is proxy ARP?
Each router decrements the TTL
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
1
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control

22. What is the format of the Flags field in the TCP header?
Sequence Number + Data payload octets + 1
Acknowledgements - checksums and timers
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
Local Internet Registry

23. Who are LIRs?
Transmission Control Protocol
Mostly large ISPs - enterprises - or academic institutions
Router#show arp
Final

24. What is the Fragment Offset field in the IPv4 header?
255.255.255.252
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
Router(config-if)#no ip proxy-arp
9

25. Which RFC defines the private IPv4 address ranges?
IANA
RFC 1918
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
They are the same byte - but the names and value interpretations are different

26. What is prefix /26 in decimal notation?
255.255.255.192
They are the same byte - but the names and value interpretations are different
4
IANA

27. Who allocates public IP address ranges to NIRs or LIRs?
RIRs
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
64
46

28. Deletes dynamic entries from the ARP cache
More Fragments follow
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Sequence Number
Time to Live

29. What is FIN?
Echo
All Internet Registries
Final
Sequence Number

30. Who can assign IP address space to end user organizations?
All Internet Registries
The next sequence number that the source expects to receive from the destination
Electrical/Optical - Mechanical - Functional and Procedural
192.88.99.0/24

31. Enables debugging output for ARP transactions
ICMP Router Discovery Protocol
89
Router#debug arp
Time Exceeded

32. Which IPv4 address range is reserved for link-local addresses when DHCP fails?
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
Redirect
Used by IRDP on some operating systems to discover local routers
169.254.0.0/16

33. What is the maximum length of an IPv4 header?
60 octets
Acknowledgement
IANA
1

34. What is ECE?
88
RIRs
Reset
ECN-Echo

35. Which IPv4 address range is reserved for IPv6 to IPv4 (6to4) relays (RFC 3068)?
Padding of zeros to ensure that the header ends on a 32-bit boundary
The next sequence number that the source expects to receive from the destination
255.255.255.248
192.88.99.0/24

36. What is gratuitous ARP?
RIRs
Router(config)#arp {ip-address} {mac-address} arpa
An ARP request issued by a host with its own IPv4 address as the target address
They are the same byte - but the names and value interpretations are different

37. What is the format of a UDP header?
Internet Control Message Protocol
IPv4 and IPv6
89
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)

38. Adds a permanent static ARP entry for an Ethernet host
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
Application
Time Exceeded
Router(config)#arp {ip-address} {mac-address} arpa

39. What is the IPv4 protocol number for UDP?
Internet Control Message Protocol
Sequence Numbers
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
17

40. What is prefix /30 in decimal notation?
Padding of zeros to ensure that the header ends on a 32-bit boundary
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
NIRs
255.255.255.252

41. Specifies the format in which subnet masks are displayed in show command output
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
6
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
RFC 791

42. How does the layers of the TCP/IP protocol suite map to the 7 layers of the OSI model?
RIPv1 and IGRP
RFC 791
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
192.0.2.0/24

43. What is the ARP Hardware address length value for Ethernet?
IPv4 and IPv6
6
Acknowledgements - checksums and timers
1

44. What is ICMP Type 0?
Echo Reply
Router Advertisement
Router(config-if)#no ip proxy-arp
Router#clear arp-cache [{interface {interface}} | {ip-address}]

45. What is the most commonly used Option field in the TCP header?
ECN-Echo
ICANN
192.0.2.0/24
Maximum Segment Size (MSS)

46. What is the IPv4 Protocol number for TCP?
255.255.255.248
LIRs
Internet Service Provider
6

47. What is the ARP Operation value for a Reverse ARP Request?
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
17
3
0.0.0.0/8

48. What is the formula to calculate the next Sequence Number based on the Sequence Number of the current TCP segment?
IANA
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
An ARP request issued by a host with its own IPv4 address as the target address
Sequence Number + Data payload octets + 1

49. Which IPv4 address range is reserved for use in documentation and example code?
Router Advertisement
Internet Service Provider
192.0.2.0/24
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)

50. What is the IPv4 Protocol number for GRE?
RIRs
Router(config-if)#no ip redirects
47
Padding of zeros to ensure that the header ends on a 32-bit boundary