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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 IPv4 Protocol number for EIGRP?
88
9
192.0.2.0/24
46

2. What is the function of ICMP redirect messages?
IPv4 and IPv6
IANA
8
Used by routers to notify hosts of another router on the data link that should be used for a particular destination

3. Who allocates public IP address ranges to NIRs or LIRs?
1
1
RIRs
192.88.99.0/24

4. What is OSI?
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);
169.254.0.0/16
Open Systems Interconnection
4

5. What is the minimum length of an IPv4 header?
Length of header in words (32-bit)
Used by a host to obtain the IPv4 address associated with its own MAC address
20 octets
Congestion Window Reduced

6. What is prefix /27 in decimal notation?
Local Internet Registry
255.255.255.224
Acknowledgement
20 octets

7. What is the ARP Protocol type value for IPv4?
Maximum Segment Size (MSS)
4
0x0800
255.255.255.240

8. 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
4
DHCP
IANA

9. What is the format of the ToS byte in the IPv4 header?
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Open Systems Interconnection
ECN-Echo
Windowing

10. What are classful routing protocols?

11. What is the ARP Operation value for an Inverse ARP Request?
Router(config)#arp {ip-address} {mac-address} arpa
Protocols that include subnet masks in their routing updates
8
Internet Corporation for Assigned Network Numbers

12. What is LIR?
9
Local Internet Registry
Host-to-host
RIPv1 and IGRP

13. What is ICMP Type 10?
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)
Used by a host to obtain the IP address associated with another host's MAC address
Router Selection
Maximum Segment Size (MSS)

14. Which IPv4 address range is reserved for link-local addresses when DHCP fails?
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);
Loose source routing; Strict source routing; Record route; Timestamp
Data Offset
169.254.0.0/16

15. Disables proxy ARP on all interfaces
20 octets
Electrical/Optical - Mechanical - Functional and Procedural
1
Router(config)#ip arp proxy disable

16. What is the ARP Operation value for an ARP Request?
1
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
Loose source routing; Strict source routing; Record route; Timestamp
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)

17. What is the format of the Flags field in the IPv4 header?
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
Padding of zeros to ensure that the header ends on a 32-bit boundary
Router(config-if)#arp timeout {seconds}
Reserved (1-bit); DF (1-bit); MF (1-bit)

18. What is SYN?
Synchronize
255.255.255.252
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)
Sequence Number + Data payload octets + 1

19. What is the name of the queuing and forwarding of IP packets based on DiffServ?
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
More Fragments follow
Per-Hop Behaviour (PHB)
6

20. What is the value of the TCP Reserved field?
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111
Subtract Header Length field from Total Length field
0
1

21. What is ECE?
Identifier; Flags and Fragmentation Offset
ECN-Echo
Host-to-host
DSCP (6-bit); ECN (2-bit)

22. Which IPv4 address range is reserved for use in documentation and example code?
IANA
192.0.2.0/24
255.255.255.192
Uniquely identify every application in the network

23. Which protocol has mostly replaced Reverse ARP?
2
DHCP
The next sequence number that the source expects to receive from the destination
Router(config)#ip arp proxy disable

24. Who owns the processes by which public IP address space and AS numbers are allocated and assigned?
ICANN
RFC 1918
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
IP Precedence (3-bit); ToS (4-bit); Reserved (1-bit)

25. What is TCP?
88
Host-to-host
Transmission Control Protocol
20 octets

26. What is the format of an IPv4 header?
Number of octets to be added to the Sequence Number to indicate the end of the urgent data
Router#show arp
Used by IRDP on some operating systems to discover local routers
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);

27. What are the protocol categories that describe the physical layer?
Electrical/Optical - Mechanical - Functional and Procedural
47
URG flag set
Used by IRDP on some operating systems to discover local routers

28. What are the uses of gratuitous ARP?
Protocols that don't include subnet masks in their routing updates
Internet Service Provider
Method where routers - by responding to ARP requests for IP addresses in different subnets - make themselves available to hosts with no default gateway configured
Duplicate address checks; Advertise new data-link identifiers; Update the ARP caches of hosts

29. Who is responsible for the global coordination of the DNS Root - IP addressing - and other Internet protocol resources?
Data Offset
4
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
IANA

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

31. What is the first octet rule for IPv4 address classes in decimal?
0
Class A 1-126; Class B 128-191; Class C 192-223; Class D 224-239; Class E 240-254
60 octets
Acknowledgements - checksums and timers

32. What mechanism is used by TCP to provided ordered segment delivery?
Loose source routing; Strict source routing; Record route; Timestamp
Sequence Numbers
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
Sequence Number

33. What is prefix /30 in decimal notation?
255.255.255.252
Windowing
Time to Live
Router(config-if)#no ip redirects

34. What is the format of the TCP Header Length field?
Reserved (1-bit); DF (1-bit); MF (1-bit)
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
6
Length of header in words (32-bit)

35. What is ACK?
Acknowledgement
ICANN and IANA
More Fragments follow
ICANN

36. What is prefix /28 in decimal notation?
1
Sequence Numbers
DSCP (6-bit); ECN (2-bit)
255.255.255.240

37. What is a TCP Acknowledgement Number?
192.88.99.0/24
Identifier; Flags and Fragmentation Offset
3
The next sequence number that the source expects to receive from the destination

38. What are the IP Precedence values?
Router Selection
1
Source Port (16-bit); Destination Port (16-bit); UDP Length (16-bit); Checksum (16-bit)
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control

39. What is ICMP?
Internet Corporation for Assigned Network Numbers
RFC 3330
Internet Control Message Protocol
Used by IRDP on some operating systems to discover local routers

40. What is RST?
Reset
Router(config)#arp {ip-address} {mac-address} arpa
64
Transmission Control Protocol

41. Enables debugging output for ARP transactions
64
IANA
Router#debug arp
8

42. What is the IPv4 Protocol number for GRE?
Mostly large ISPs - enterprises - or academic institutions
255.255.255.192
47
CWR (1-bit); ECE (1-bit); URG (1-bit); ACK (1-bit); PSH (1-bit); RST (1-bit); SYN (1-bit); FIN (1-bit)

43. What mechanisms are used by TCP to provide reliable segment delivery?
ICANN and IANA
Largest segment size that the sender is willing to accept
192.0.2.0/24
Acknowledgements - checksums and timers

44. Displays the ARP cache of a router
Router#show arp
IANA
Each router decrements the TTL
DSCP (6-bit); ECN (2-bit)

45. Adds a permanent static ARP entry for an Ethernet host
4
Router(config)#arp {ip-address} {mac-address} arpa
Subtract Header Length field from Total Length field
Class A 0; Class B 10; Class C 110; Class D 1110; Class E 1111

46. What is the recommended default TTL?
6
64
Final
ECN-Echo

47. What is ICMP Type 5?
RFC 1918
Transmission Control Protocol
Redirect
Application

48. What are classless routing protocols?
They are the same byte - but the names and value interpretations are different
Protocols that include subnet masks in their routing updates
Push
Router(config-if)#arp timeout {seconds}

49. What is ICMP Type 8?
0 Routine; 1 Priority; 2 Immediate; 3 Flash; 4 Flash Override; 5 Critical; 6 Internetwork Control; 7 Network Control
Echo
The next sequence number that the source expects to receive from the destination
NIRs

50. Which RFC defines the special use IPv4 address ranges?
RFC 3330
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
Push
127.0.0.0/8