IPv4 Subnetting Flashcards Preview

CompTIA N+ N10-006 > IPv4 Subnetting > Flashcards

Flashcards in IPv4 Subnetting Deck (30)
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1

What does the subnet mask do?

Identifies the network and host portion of an address

2

What are IP address ranges?

A: 1-126.x.x.x
B: 128-191.x.x.x
C: 192-223.x.x.x

3

What is TTL (time to live)?

The time for a ping request to expire

4

What are the private IP address ranges?

A: 10.x.x.x
B: 172.16-31.x.x
C: 192.168.x.x

5

What do private addresses use to resolve to a public IP address?

NAT
Network Address Translation

6

What Base does Binary use?

Base 2

7

What Base does Decimal use?

Base 10

8

What Base does Hexadecimal use?

Base 16

9

How do you convert decimal to binary?

Find the highest common denominator of a powers of 2 that goes into the decimal number. For an octet 2^0 - 2^7

10

When subnetting, how are each of the octet bits allocated?

Contiguously from left to right
Think Network | Host mentality
11111111.11111111.11111111.00000000
Not:
11011111.11111111.11111101.00000000

11

How does the prefix length correspond with the subnet number?

/8 = 255.0.0.0 - Class A default
/9 = 255.128.0.0
/10 = 255.192.0.0
/11 = 255.224.0.0
/12 = 255.240.0.0
/13 = 255.248.0.0
/14 = 255.252.0.0
/15 = 255.254.0.0
/16 = 255.255.0.0 Class B default

12

What are the valid host addresses within a subnet range? (when sacrificing host bits)

First host: subnet + 1
Last host: subnet - 2

13

What is the broadcast address for a subnet range? (when sacrificing host bits)

next subnet - 1

14

What are the two components of an IP address?

Network | Host

15

What are the components of a subnetted IP address?

Network | Subnet | Host

16

What determines if you can assign a host an IP address on a given subnetwork address?

You are not able to assign an IP address to a host if it is a subnetwork address with the host portion all 0s

17

How do you calculate number of hosts on a subnet?

32 - prefixlength = h
2^h - 2 = number of hosts available

18

How do you calculate the subnet of an IP address?

(Last network octet / Block size) * Block size

*remove remainder
*host octets will be 0 (everything to the right of network octet)

19

How do you calculate the subnets possible for a given network?

Subnets = 2^bits sacrificed from host

20

How do you calculate the subnet addresses for a given network?

Subnet is default 0.0.0.0 + Block size each time for number of subnets possible

21

How do you determine Block size for a subnet?

Last bit used in octet

In this case 2nd octet:
255.255.0.0 Block size = 2^0 = 1
255.252.0.0 Block size = 2^2 = 4

22

What does the summary address do?

Identifies which bits of an octet are in common
(Simplifies the routing table)

23

How do you summarise a network?

Determine common octets + common consecutive bits in changing octet
Take value of bits and change last network octet + prefixlength based on bits used

24

What is mask value?

Increments from left to right in a given octet based on bits used

25

What is a wildcard mask?

Inverted subnet mask

26

How do you determine the wildcard mask for a boundary that is not clean (/8, 16, /24)

Block size - 1
(in mask value's position)

27

What is VLSM?

Variable Length Subnet Mask

28

How do you configure a VLSM?

List mask and subnets in order of most hosts required
After last subnet on a network increment by its block size again then start the next network
Repeat for point to point WAN links

29

What public address range is used for multicast?

224-239.x.x

30

How do you determine largest remaining block in VLSM?

32 - Address prefix length (h)
2^h total host addresses that can be allocated
Largest remaining = 2^h - VLSMs