Chapter 8 BB Flashcards
What are 4 benefits of subnetting? Pg 235
Reduced network traffic, optimized network performance, simplified management, and facilitated spanning of large geographical distances.
What 3 steps should you follow before creating subnets? Pg 235
- Determine the number of required network IDs.
- Determine the number of required host IDs per subnet.
- Based on the previous requirements, create the following:
- one subnet mask for your entire network
- a unique subnet ID for each physical segment
- a range of host IDs for each subnet
What is a subnet mask? Pg 236
A subnet mask defines the network ID portion of the IP address and the host ID portion of the IP address for the recipient of IP packets.
How does the subnet mask distinguish the network ID portion from the host ID portion of an IP? Pg 237
The 32 bit subnet mask is composed of 1s and 0s. The 1s represent the positions that refer to the network.
What does it mean when a network does not need a subnet? Pg 237
That network uses a default subnet mask. Each class of address has a different default subnet mask.
What are the default subnet masks of each class of network? Pg 237
Class A: 255.0.0.0
Class B: 255.255.0.0
Class C: 255.255.255.0
What is CIDR? Pg 237
Classless Inter-Domain Routing is the method that ISPs use to allocate a number of addresses to a company or a home connection.
What is slash notation? Pg 237
A way of dictating the subnet mask. The number after the slash(/) dictates how many bits are turned on (1s). For example 127.16.10.32/8 means that the first 8 bits are turned on, meaning this is a class A default subnet mask.
What is the maximum number of bits that can be turned on for the subnet mask? Pg 237
30
Which numbers of bits(slash notation) can be turned on for which network classes? Pg 238-239
Class A: /8 thru /15
Class A&B: /16 thru /23
Class A&B&C: /24 thru /30
After choosing a possible subnet mask but need to determine the number of subnets, valid hosts, and broadcast addresses of a subnet that the mask provides, what 5 questions should you ask yourself? Pg 239
– How many subnets does the chosen subnet mask produce?
– How many valid hosts per subnet are available?
– What are the valid subnets?
– What’s the broadcast address of each subnet?
– What are the valid hosts in each subnet?
(answering these questions will be covered in the following 5 cards)
How do you answer “How many subnets?”? Pg 240
2^x, where x is the number of masked bits.
How do you answer “How many hosts per subnet?”? Pg 240
(2^y)-2, where y is the number of unmasked bits
How do you answer “What are the valid subnets?”? Pg 240
256 - subnet mask = block size, or increment number.
How do you answer “What’s the broadcast address for each subnet?”? Pg 240
The broadcast address is always the number right before the next subnet.
