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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 ARP Operation value for an ARP Reply?
2
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
Used by a host to obtain the IP address associated with another host's MAC address
Padding of zeros to ensure that the header ends on a 32-bit boundary

2. Which IPv4 address range is reserved for IPv6 to IPv4 (6to4) relays (RFC 3068)?
IPv4 and IPv6
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Used by a host to obtain the IP address associated with another host's MAC address
192.88.99.0/24

3. What is the format of the ToS byte in the IPv4 header?
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
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
169.254.0.0/16

4. What routing protocols are classful?
Host-to-host
ECN-Echo
RIPv1 and IGRP
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)

5. What is the IPv4 Protocol number of RSVP?
Uniquely identify every application in the network
IPv4 and IPv6
The next sequence number that the source expects to receive from the destination
46

6. Why must the header checksum of an IPv4 packet be recalculated at every router?
1
LIRs
Electrical/Optical - Mechanical - Functional and Procedural
Each router decrements the TTL

7. What is the IPv4 Protocol number for IP in IP encapsulation?
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);
255.255.255.192
4
Router#debug arp

8. What are the steps to subnet an IPv4 address?
Urgent
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
2
Router Selection

9. What is the format of an IPv4 header?
Mostly large ISPs - enterprises - or academic institutions
255.255.255.240
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);
60 octets

10. What is ICMP Type 3?
Destination Unreachable
2
Padding of zeros to ensure that the header ends on a 32-bit boundary
Local Internet Registry

11. What is OSI?
Router(config)#arp {ip-address} {mac-address} arpa
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
Open Systems Interconnection
Used by a host to obtain the IPv4 address associated with its own MAC address

12. Who administers and registers IP address space and AS numbers within a region?
RIRs
2
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
255.255.255.248

13. What is the ARP Hardware address length value for Ethernet?
6
Push
Internet
An ARP request issued by a host with its own IPv4 address as the target address

14. What is the ARP Hardware type value for Ethernet?
Host-to-host
169.254.0.0/16
Don't Fragment
1

15. What is the formula to calculate the next Sequence Number based on the Sequence Number of the current TCP segment?
Windowing
88
Sequence Number + Data payload octets + 1
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)

16. What is a TCP Acknowledgement Number?
Router(config-if)#no ip redirects
The next sequence number that the source expects to receive from the destination
0.0.0.0/8
Padding of zeros to ensure that the header ends on a 32-bit boundary

17. What mechanism is used by TCP to provided ordered segment delivery?
Acknowledgement
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
Sequence Numbers
88

18. What is ISP?
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)
Internet Assigned Numbers Authority
2
Internet Service Provider

19. What TCP/IP protocol suite layer corresponds to the network layer of the OSI model?
Internet
URG flag set
1
Sequence Number

20. Who is responsible for the global coordination of the DNS Root - IP addressing - and other Internet protocol resources?
IPv4 and IPv6
IANA
8
198.18.0.0/15

21. What field identifies where the TCP encapsulated data fits within the data stream from the sender?
Internet Protocol
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
Sequence Number
Largest segment size that the sender is willing to accept

22. What is the format of the Flags field in the TCP header?
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
Transmission Control Protocol
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
Minimize Delay (1-bit); Maximise Throughput (1-bit); Maximise Reliability (1-bit); Minimize Monetary Cost (1-bit)

23. Which IPv4 address range is reserved for use in documentation and example code?
192.0.2.0/24
RIPv1 and IGRP
ICMP Router Discovery Protocol
DHCP

24. What are the most frequently used options in the IPv4 header?
Maximum Segment Size (MSS)
Loose source routing; Strict source routing; Record route; Timestamp
9
Acknowledgement

25. What are classless routing protocols?
Router Advertisement
LIRs
255.255.255.128
Protocols that include subnet masks in their routing updates

26. Who administers and registers public IP address space and AS numbers within a country or economic unit?
64
198.18.0.0/15
NIRs
Internet Service Provider

27. What is the other name for the TCP Header Length field?
Host-to-host
RFC 1918
Push
Data Offset

28. What is CWR?
1
Congestion Window Reduced
4
Internet Control Message Protocol

29. What is added after the Option field in the TCP header?
Router(config)#arp {ip-address} {mac-address} arpa
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
Loose source routing; Strict source routing; Record route; Timestamp

30. What is the IPv4 Protocol number for EIGRP?
Data Offset
3
88
Used by a host to obtain the IP address associated with another host's MAC address

31. Who can assign IP address space to end user organizations?
Protocols that don't include subnet masks in their routing updates
IANA
All Internet Registries
Both the TCP header and the encapsulated data

32. What is covered by the TCP Checksum field?
RFC 3330
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Both the TCP header and the encapsulated data
More Fragments follow

33. What is the format of a TCP header?
LIRs
Padding of zeros to ensure that the header ends on a 32-bit boundary
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
Time to Live

34. What is the first octet rule for IPv4 address classes in decimal?
Push
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
Subtract Header Length field from Total Length field

35. Who are LIRs?
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Mostly large ISPs - enterprises - or academic institutions
Time to Live
Router#show arp

36. What IPv4 header fields are used for fragmentation?
127.0.0.0/8
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
169.254.0.0/16
Identifier; Flags and Fragmentation Offset

37. What is ICMP Type 11?
Time Exceeded
More Fragments follow
RFC 1918
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control

38. What is proxy ARP?
255.255.255.252
Used by routers to notify hosts of another router on the data link that should be used for a particular destination
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
Final

39. Which RFC defines IPv4?
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
Internet Assigned Numbers Authority
RFC 791
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control

40. What is the IPv4 Protocol number for GRE?
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
Per-Hop Behaviour (PHB)
Open Systems Interconnection
47

41. What are the private IPv4 address ranges?
4
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
Router Advertisement
Internet Control Message Protocol

42. What is ICMP?
Echo Reply
Internet Corporation for Assigned Network Numbers
Internet Control Message Protocol
RIRs

43. Which IPv4 address range is reserved for link-local addresses when DHCP fails?
Redirect
255.255.255.224
169.254.0.0/16
Urgent

44. What is the ARP Operation value for a Reverse ARP Reply?
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
4
198.18.0.0/15
255.255.255.192

45. What is IP?
2
Maximum Segment Size (MSS)
Internet Protocol
Internet Service Provider

46. What is the format of an ICMP header?
NIRs
ICANN and IANA
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
Host-to-host

47. Which IPv4 address range is reserved for self-identification on a local subnet?
Urgent
Each router decrements the TTL
Subtract Header Length field from Total Length field
0.0.0.0/8

48. What is PSH?
RFC 3330
Used by a host to obtain the IPv4 address associated with its own MAC address
Push
More Fragments follow

49. What is prefix /29 in decimal notation?
Largest segment size that the sender is willing to accept
64
255.255.255.248
ICMP Router Discovery Protocol

50. Who group public IPv4 address space by major geographic region?
ICANN and IANA
1
Router(config-if)#no ip redirects
They are the same byte - but the names and value interpretations are different