Networking Concepts (5) Flashcards
To which class does the following IPv4 address belong: 190.126.14.251?
Class A
Class B
Class C
Class B
All Class B addresses have first octet values between 128 and 191. The first octet range of a Class A address is 1 to 126, and the Class C first octet range is 192 to 223. Class D addresses have a first octet range of 224 to 239
Classless Inter-Domain Routing (CIDR) is a standard for IP addressing that includes the ability to create subnets using any number of IP address bits, rather than using 8-bit blocks. Which of the following terms describes this ability?
VLSM
APIPA
VLAN
VLSM
Variable-length subnet masking (VLSM) describes the process of subnetting a network address by assigning an arbitrary number of host bits as subnet bits, providing administrators with great flexibility over the number of subnets created and the number of hosts in each subnet. Automatic Private IP Addressing (APIPA) is the process by which a DHCP client assigns itself an IP address when no DHCP servers are accessible. Virtual local area networks (VLANs) are logical structures used to create separate broadcast domains on a large, switched network. Extended Unique Identifier-64 (EUI-64) is an addressing method used to create IPv6 link local addresses out of media access control (MAC) addresses
Ralph has been instructed to use the network address 10.12.0.0/14 for the new network he is installing. What subnet mask value should he use when configuring his computers?
- 248.0.0
- 252.0.0
- 254.0.0
255.252.0.0
The 14-bit prefix indicated in the network address will result in a mask with 14 ones followed by 18 zeroes. Broken into 8-bit blocks, the binary mask value is as follows:
11111111 11111100 00000000 00000000
Converted into decimal values, this results in a subnet mask value of 255.252.0.0
Ed has been hired to design a company’s network. The company has an assigned Class C network address of 192.168.30.0. Ed’s client wants the network to be configured with 10 subnets, each with 14 hosts. Is this configuration possible with the given address, and if so, how many subnets and hosts can Ed create on the network?
Yes, this will work. By using 4 subnet bits, it is possible for Ed to create up to 16 subnets. He can then use the remaining 4 host bits to create 14 hosts on each subnet.
No, this will not work. A Class C address cannot be subnetted to create 8 subnets.
No, this will not work. Although there are sufficient bits available to create 10 subnets, there are not enough bits left over for Ed to create 14 hosts per subnet.
Yes, this will work. By using 4 subnet bits, it is possible for Ed to create up to 16 subnets. He can then use the remaining 4 host bits to create 14 hosts on each subnet.
In this scenario, the company has a Class C Internet Protocol (IP) address, which consists of 24 network bits and 8 host bits. The company wants 10 subnets and 14 hosts per subnet, so Ed must subdivide the 8 host bits into subnet and host bits. He can allocate 4 of the 8 host bits for subnets, enabling him to create up to 16 subnets. This leaves 4 bits for host addresses, enabling Ed to create 14 hosts per subnet
What is the greatest number of subnets you can create with a Class A IPv4 address if you use a 14-bit subnet identifier?
16,382
16,384
16,384
The formula for calculating the number of subnets you can create using a subnet identifier of a given length is 2x, where x is the number of bits in the subnet identifier. Therefore, with a 14-bit subnet, you can conceivably create 214, or 16,384, subnets
Alice has been asked to design her company’s Internet Protocol (IP) addressing scheme. The company has been assigned Class C network address of 192.168.30.0. Alice’s director wants 4 subnets with 28 hosts per subnet. How many bits are required for subnets? How many bits are required for hosts? What will the new subnet mask be for this network?
3 subnet bits, 5 host bits, and subnet mask 255.255.255.240
4 subnet bits, 3 host bits, and subnet mask 255.255.255.248
3 subnet bits, 5 host bits, and subnet mask 255.255.255.224
3 subnet bits, 5 host bits, and subnet mask 255.255.255.224
In this scenario, the last byte of the IP address assigned to the company must be subdivided into 3 subnet bits and 5 host bits. The 3 subnet bits will give Alice up to 8 subnets, with 5 host bits for up to 30 hosts per subnet. The new subnet mask is 255.255.255.224. The 224 is the decimal equivalent of the binary value 11100000, which represents the 3 subnet bits and the 5 host bits
A network interface adapter in a workstation has a hexadecimal MAC address of 001F9EFC7AD0. Which of the following would be the adapter’s IPv6 link local address based on its EUI-64 value?
FE80::001F:9EFF:FEFC:7AD0
FE80::FFFE:021F:9EFC:7AD0
FE80::FF00:1F9E:FC7A:D0FE
FE80::021F:9EFF:FEFC:7AD0
FE80::021F:9EFF:FEFC:7AD0
To convert a MAC address to an Extended Unique Identifier (EUI-64), you split the 6-byte MAC address into two 3-byte halves and insert the 2-byte value FFFE in between, as follows:
001F9E FFFE FC7AD0
Then, you change the seventh bit in the first byte, the universal/local bit, from 0 to 1, indicating that this is a locally created address. This results in a binary first byte value of 00000010, which converts to 02 in hexadecimal.
Finally, you add the IPv6 link local prefix FE80::/10, resulting in the following complete address:
FE80::021F:9EFF:FEFC: 7AD0
All of the other answers either insert the FFFE bytes in the wrong place or fail to change the universal/local bit.
The default mask for a Class B network is 255.255.0.0. How many subnet bits do you need to create 600 subnets with 55 hosts per subnet, and what is the new subnet mask for the network?
10 subnet bits with a subnet mask of 255.255.255.192
9 subnet bits with a subnet mask of 255.255.255.128
10 subnet bits with a subnet mask of 255.255.224.0
10 subnet bits with a subnet mask of 255.255.255.192
A standard Class B address with a mask of 255.255.0.0 has 16 bits that can be used for subnets and hosts. To get 600 subnets, you must use 10 of the available bits, which gives you up to 1024 subnets. This leaves 6 host bits, which gives you up to 62 hosts per subnet, which exceeds the requirement of 55 requested by the client. Using 9 bits would give you only 510 subnets, while 11 bits would give you 2046 subnets but leave you only 5 bits for a maximum of 30 hosts, which is not enough
What is the greatest number of host addresses you can create on a single subnet of a network with the following address: 172.16.0.0/20?
142
144
4,094
4,094
The formula for calculating the number of hosts you can create using a host identifier of a given length is 2x–2, where x is the number of bits in the host identifier. You cannot create a host with an address of all zeroes or all ones, which is why you subtract 2. On a network that uses 20 bits for network identification, 12 bits are left for the host identifier. Using those 12 bits, you can create 212–2 or 4,094 host addresses
Ralph has a Class B network with a subnet mask of 255.255.248.0. How many subnets can he create, and how many hosts can he create per subnet?
64 subnets and 2046 hosts
32 subnets and 2046 hosts
30 subnets and 1022 hosts
32 subnets and 2046 hosts
With a Class B subnet mask of 255.255.248.0, the binary form of the third and fourth bytes is 11111000 00000000. There are 5 subnet bits, providing up to 32 subnets and 11 host bits, providing up to 2046 hosts
Convert the binary mask 11111111.11111111.11100000.00000000 into its equivalent decimal value. What is the decimal representation of this mask?
- 255.224.0
- 255.240.0
- 255.248.0
255.255.224.0
The decimal value for 11111111 is 255, the value for 11100000 is 224, and the value for 00000000 is 0, so the mask is 255.255.240.0
If you have a network address of 192.168.1.32/27, what is the valid range of host addresses you can use for your workstations?
- 168.1.33 through 192.168.1.63
- 168.1.33 through 192.168.1.62
- 168.1.34 through 192.168.1.62
192.168.1.33 through 192.168.1.62
With a network address of 192.168.1.32 and 27 mask bits, the subnet mask value is 11111111.11111111.11111111.11100000 in binary form, or 255.255.255.224 in decimal form. This leaves 5 bits for the host identifier. The valid range of host bits is therefore 00001 (1) through 11110 (30). This gives you a range of 192.168.1.32 + 1 (33) through 192.168.1.32 + 30 (62)
Alice has been assigned the network address 172.21.0.0/22 for the creation of a new department network in her company. How many host addresses does she have available to her?
510
512
1022
1022
To calculate the number of host addresses available, Alice must determine the number of host bits in the address, which is 10, raise 2 to that power, and subtract 2 for the network and broadcast addresses, which are unusable for hosts. The formula is therefore 2x–2. 210–2=1022
Automatic Private IP Addressing (APIPA) assigns IPv4 addresses from which of the following classes to Dynamic Host Configuration Protocol (DHCP) clients that cannot contact a DHCP server?
Class A
Class B
Class C
Class B
When a DHCP client cannot access a DHCP server, APIPA assigns it a Class B address in the range 169.254.0.0 to 169.254.255.255
Which of the following Internet Protocol (IP) address classes identifies multicast addresses?
Class B
Class C
Class D
Class D
Class D addresses are used for multicast transmissions. Class A, Class B, and Class C addresses are used for unicast transmissions. Class E is for experimental use only
