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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 format of an ARP packet?
Internet Assigned Numbers Authority
Sequence Numbers
The next sequence number that the source expects to receive from the destination
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

2. What routing protocols are classful?
IPv4 and IPv6
Mostly large ISPs - enterprises - or academic institutions
RIPv1 and IGRP
URG flag set

3. What is the format of the Flags field in the TCP header?
RFC 1918
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
1
2

4. What is the format of an ICMP header?
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
4
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
1

5. What is the content of the Maximum Segment Size (MSS) in the Option field of the TCP header?
Largest segment size that the sender is willing to accept
169.254.0.0/16
DHCP
Used by a host to obtain the IP address associated with another host's MAC address

6. What is the IPv4 Protocol number for ICMP?
47
1
More Fragments follow
RFC 3330

7. Enables debugging output for ARP transactions
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
Router#debug arp
Reset

8. Specifies the format in which subnet masks are displayed in show command output
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
Router Advertisement
URG flag set
Used by a host to obtain the IPv4 address associated with its own MAC address

9. What are the protocol categories that describe the physical layer?
Electrical/Optical - Mechanical - Functional and Procedural
198.18.0.0/15
Mostly large ISPs - enterprises - or academic institutions
8

10. What is the first octet rule for IPv4 address classes in decimal?
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Padding of zeros to ensure that the header ends on a 32-bit boundary
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
8

11. How does the layers of the TCP/IP protocol suite map to the 7 layers of the OSI model?
4
Echo Reply
2
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application

12. What TCP/IP protocol suite layer corresponds to the physical and data link layers of the OSI model?
8
2
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
Network interface

13. What is prefix /25 in decimal notation?
255.255.255.128
Windowing
0x0800
0

14. What are the private IPv4 address ranges?
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Socket
Used by IRDP on some operating systems to discover local routers
IANA

15. Disables proxy ARP on an interface
Router(config-if)#no ip proxy-arp
Loose source routing; Strict source routing; Record route; Timestamp
2
RFC 3330

16. What is the value of the TCP Reserved field?
ICANN
Maximum Segment Size (MSS)
RFC 3330
0

17. Disables the sending of ICMP redirect messages
Router(config-if)#no ip redirects
Socket
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
Open Systems Interconnection

18. What is ICMP Type 5?
Windowing
Redirect
4
RFC 791

19. Which RFC defines the private IPv4 address ranges?
Network interface
ECN-Echo
RFC 1918
198.18.0.0/15

20. What is PSH?
Sequence Number
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
6
Push

21. Deletes dynamic entries from the ARP cache
URG flag set
Protocols that include subnet masks in their routing updates
Internet
Router#clear arp-cache [{interface {interface}} | {ip-address}]

22. Who assigns IP address space to its own customers?
DSCP (6-bit); ECN (2-bit)
LIRs
ICANN
Loose source routing; Strict source routing; Record route; Timestamp

23. What is FIN?
Host-to-host
Data Offset
Per-Hop Behaviour (PHB)
Final

24. What is IRDP?
Open Systems Interconnection
ICMP Router Discovery Protocol
Identifier; Flags and Fragmentation Offset
Sequence Number + Data payload octets + 1

25. Who allocates public IP address ranges to NIRs or LIRs?
6
Windowing
Internet Corporation for Assigned Network Numbers
RIRs

26. What is the formula to calculate the next Sequence Number based on the Sequence Number of the current TCP segment?
Sequence Number + Data payload octets + 1
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
Used by a host to obtain the IPv4 address associated with its own MAC address
6

27. Who is responsible for maintaining the official assignments of TCP and UDP port numbers for specific uses?
88
DSCP (6-bit); ECN (2-bit)
IANA
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application

28. What is added after the option field in the IPv4 header?
46
Acknowledgement
Padding of zeros to ensure that the header ends on a 32-bit boundary
ICANN

29. What is LIR?
89
Router(config)#arp {ip-address} {mac-address} arpa
Local Internet Registry
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}

30. What TCP/IP protocol suite layer corresponds to the network layer of the OSI model?
Destination Unreachable
Internet
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16

31. What is the ARP Operation value for a Reverse ARP Reply?
4
Maximum Segment Size (MSS)
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
Time to Live

32. Configures how long a dynamically learned protocol address and its corresponding hardware address remains in the ARP cache
255.255.255.224
Router(config-if)#arp timeout {seconds}
0
Sequence Number + Data payload octets + 1

33. What is the prerequisite for using the Urgent Pointer field in the TCP header?
Uniquely identify every application in the network
Largest segment size that the sender is willing to accept
RIRs
URG flag set

34. Which IPv4 address range is reserved for loopback testing?
Host-to-host
Regional Internet Registry
RIRs
127.0.0.0/8

35. What is the recommended default TTL?
64
LIRs
Reset
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)

36. What is Inverse ARP?

37. What mechanism is used by TCP to regulate the flow of segments?
They are the same byte - but the names and value interpretations are different
LIRs
Windowing
89

38. Which IPv4 address range is reserved for use in documentation and example code?
Electrical/Optical - Mechanical - Functional and Procedural
255.255.255.192
192.0.2.0/24
89

39. What is IANA?
Synchronize
Internet Assigned Numbers Authority
Socket
Sequence Numbers

40. What is the format of the DiffServ byte?
DSCP (6-bit); ECN (2-bit)
An ARP request issued by a host with its own IPv4 address as the target address
Router Advertisement
Router(config)#ip arp proxy disable

41. What is ECE?
Uniquely identify every application in the network
Application
ECN-Echo
Host-to-host

42. What is the format of a TCP header?
Time to Live
Largest segment size that the sender is willing to accept
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
2

43. What is the IPv4 Protocol number for IGMP?
Padding of zeros to ensure that the header ends on a 32-bit boundary
Subtract Header Length field from Total Length field
2
Application

44. Disables proxy ARP on all interfaces
Router(config)#ip arp proxy disable
Internet Control Message Protocol
Redirect
9

45. Adds a permanent static ARP entry for an Ethernet host
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
Router(config)#arp {ip-address} {mac-address} arpa
Internet Protocol
RIPv1 and IGRP

46. What is the format of the Flags field in the IPv4 header?
Reserved (1-bit); DF (1-bit); MF (1-bit)
Network interface
1
LIRs

47. What field identifies where the TCP encapsulated data fits within the data stream from the sender?
Internet Control Message Protocol
Sequence Number
IANA
RFC 3330

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

49. What is ARP?
192.0.2.0/24
ICMP Router Discovery Protocol
All Internet Registries
Address Resolution Protocol

50. What is the content of the TCP Window Size field?
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
Identifier; Flags and Fragmentation Offset
46