Flashcards in IPv4 Subnetting Deck (30)
What does the subnet mask do?
Identifies the network and host portion of an address
What are IP address ranges?
What is TTL (time to live)?
The time for a ping request to expire
What are the private IP address ranges?
What do private addresses use to resolve to a public IP address?
Network Address Translation
What Base does Binary use?
What Base does Decimal use?
What Base does Hexadecimal use?
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
When subnetting, how are each of the octet bits allocated?
Contiguously from left to right
Think Network | Host mentality
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
What are the valid host addresses within a subnet range? (when sacrificing host bits)
First host: subnet + 1
Last host: subnet - 2
What is the broadcast address for a subnet range? (when sacrificing host bits)
next subnet - 1
What are the two components of an IP address?
Network | Host
What are the components of a subnetted IP address?
Network | Subnet | Host
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
How do you calculate number of hosts on a subnet?
32 - prefixlength = h
2^h - 2 = number of hosts available
How do you calculate the subnet of an IP address?
(Last network octet / Block size) * Block size
*host octets will be 0 (everything to the right of network octet)
How do you calculate the subnets possible for a given network?
Subnets = 2^bits sacrificed from host
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
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
What does the summary address do?
Identifies which bits of an octet are in common
(Simplifies the routing table)
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
What is mask value?
Increments from left to right in a given octet based on bits used
What is a wildcard mask?
Inverted subnet mask
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)
What is VLSM?
Variable Length Subnet Mask
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
What public address range is used for multicast?