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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. Disables the sending of ICMP redirect messages
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16
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
Router(config-if)#no ip redirects
Transmission Control Protocol

2. What is the formula to calculate the next Sequence Number based on the Sequence Number of the current TCP segment?
2
Internet Corporation for Assigned Network Numbers
Sequence Number + Data payload octets + 1
Loose source routing; Strict source routing; Record route; Timestamp

3. What is Inverse ARP?

4. Which IPv4 address range is reserved for loopback testing?
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(config)#arp {ip-address} {mac-address} arpa
Acknowledgement
127.0.0.0/8

5. What is the ARP Operation value for an ARP Reply?
Internet Protocol
Per-Hop Behaviour (PHB)
Host-to-host
2

6. What routing protocols are classful?
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
Both the TCP header and the encapsulated data
Maximum Segment Size (MSS)
RIPv1 and IGRP

7. Who owns the processes by which public IP address space and AS numbers are allocated and assigned?
Electrical/Optical - Mechanical - Functional and Procedural
Acknowledgements - checksums and timers
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
ICANN

8. Adds a permanent static ARP entry for an Ethernet host
Length of header in words (32-bit)
0x0800
Router(config)#arp {ip-address} {mac-address} arpa
1

9. Which protocol has mostly replaced Reverse ARP?
DHCP
Internet Protocol
Regional Internet Registry
Electrical/Optical - Mechanical - Functional and Procedural

10. Deletes dynamic entries from the ARP cache
Router#clear arp-cache [{interface {interface}} | {ip-address}]
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Router Selection
ICMP Router Discovery Protocol

11. What is the format of a UDP header?
Congestion Window Reduced
88
Sequence Number
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)

12. What are classless routing protocols?
Protocols that include subnet masks in their routing updates
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
IANA
They are the same byte - but the names and value interpretations are different

13. What is the format of the ToS byte in the IPv4 header?
Sequence Number
1
6
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)

14. What is RIR?
Regional Internet Registry
Protocols that include subnet masks in their routing updates
0
DSCP (6-bit); ECN (2-bit)

15. What is the minimum length of an IPv4 header?
192.88.99.0/24
Router(config)#ip arp proxy disable
20 octets
Sequence Number + Data payload octets + 1

16. What is the ARP Operation value for a Reverse ARP Request?
Maximum Segment Size (MSS)
3
Sequence Numbers
2

17. Who group public IPv4 address space by major geographic region?
Redirect
Largest segment size that the sender is willing to accept
ICANN and IANA
Loose source routing; Strict source routing; Record route; Timestamp

18. What is Reverse ARP?
The next sequence number that the source expects to receive from the destination
Offset - in units of eight octets - from the beginning of the original header to the beginning of the fragment
Used by a host to obtain the IPv4 address associated with its own MAC address
Maximum Segment Size (MSS)

19. What is the value of the TCP Reserved field?
Router#show arp
Echo
Uniquely identify every application in the network
0

20. What is the IPv4 Protocol number for EIGRP?
Uniquely identify every application in the network
1
Reserved (1-bit); DF (1-bit); MF (1-bit)
88

21. What is FIN?
8
Final
Urgent
RFC 1918

22. What is the difference between the ToS and the DiffServ byte?
ECN-Echo
They are the same byte - but the names and value interpretations are different
Echo Reply
Network interface

23. What are the uses of gratuitous ARP?
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts
1-2 Network interface; 3 Internet; 4 Host-to-host; 5-7 Application
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Congestion Window Reduced

24. What is a TCP Acknowledgement Number?
4
The next sequence number that the source expects to receive from the destination
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
Internet Assigned Numbers Authority

25. What is the format of the Flags field in the TCP header?
Don't Fragment
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)
More Fragments follow

26. What is IANA?
Urgent
Internet Assigned Numbers Authority
3
ICANN and IANA

27. What are the most common IP version numbers?
Internet Service Provider
255.255.255.224
RIRs
IPv4 and IPv6

28. What is proxy ARP?
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
NIRs
Subtract Header Length field from Total Length field
0x0800

29. What is TCP?
Transmission Control Protocol
1
Uniquely identify every application in the network
10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16

30. What is the IPv4 Protocol number for IP in IP encapsulation?
Per-Hop Behaviour (PHB)
Don't Fragment
Internet Protocol
4

31. What is the format of an ICMP header?
Don't Fragment
Type (8-bit); Code (8-bit); Checksum (16-bit); Variable fields
Router#show arp
2

32. What is the first octet rule for IPv4 address classes in binary?
Protocols that don't include subnet masks in their routing updates
ECN-Echo
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
Don't Fragment

33. What is the function of ICMP redirect messages?
Padding of zeros to ensure that the header ends on a 32-bit boundary
Internet Service Provider
Reset
Used by routers to notify hosts of another router on the data link that should be used for a particular destination

34. What is LIR?
Acknowledgement
Destination Unreachable
Transmission Control Protocol
Local Internet Registry

35. What is ICMP Type 8?
1
3
Host-to-host
Echo

36. How can the receiver determine the size of a packet's data payload based on the IPv4 header?
Subtract Header Length field from Total Length field
Each router decrements the TTL
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
Network interface

37. What is a TCP port number of an application called when it is coupled with the IP address of the server?
192.88.99.0/24
National Internet Registry
Socket
Reserved (1-bit); DF (1-bit); MF (1-bit)

38. What is ACK?
Acknowledgement
255.255.255.224
Padding of zeros to ensure that the header ends on a 32-bit boundary
LIRs

39. Which IPv4 address range is reserved for use in documentation and example code?
192.0.2.0/24
169.254.0.0/16
Transmission Control Protocol
Don't Fragment

40. What is prefix /28 in decimal notation?
Loose source routing; Strict source routing; Record route; Timestamp
ICMP Router Discovery Protocol
255.255.255.240
Socket

41. What field identifies where the TCP encapsulated data fits within the data stream from the sender?
Internet Assigned Numbers Authority
Sequence Number
IANA
IPv4 and IPv6

42. What is the IPv4 protocol number for UDP?
17
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
Protocols that include subnet masks in their routing updates
Per-Hop Behaviour (PHB)

43. What mechanism is used by TCP to provided ordered segment delivery?
IANA
Local Internet Registry
Length of header in words (32-bit)
Sequence Numbers

44. Specifies the format in which subnet masks are displayed in show command output
9
Router(config)#ip netmask-format {bit-count | decimal | hexadecimal}
1
The next sequence number that the source expects to receive from the destination

45. What is the ARP Hardware type value for Ethernet?
Router#show arp
64
1
Acknowledgement

46. What is the ARP Operation value for an Inverse ARP Reply?
4
Internet Service Provider
Padding of zeros to ensure that the header ends on a 32-bit boundary
9

47. Who administers and registers IP address space and AS numbers within a region?
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
RIRs
ICMP Router Discovery Protocol
89

48. Which RFC defines the private IPv4 address ranges?
IANA
RFC 1918
NIRs
DHCP

49. What is the IPv4 Protocol number for IGMP?
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
47
2
Router(config)#arp {ip-address} {mac-address} arpa

50. What is the most commonly used Option field in the TCP header?
Used by IRDP on some operating systems to discover local routers
255.255.255.224
Maximum Segment Size (MSS)
Echo Reply