Please enable JavaScript.
Coggle requires JavaScript to display documents.
CHAPTER 9: SUBNETTING IP NETWORKS - Coggle Diagram
CHAPTER 9: SUBNETTING IP NETWORKS
Reasons for Subnetting
Subnetting - process of segmenting a network into multiple smaller network spaces called subnetworks or Subnets.
Large networks need to be segmented into smaller sub-networks, creating smaller groups of devices and services in order to:
Control traffic by containing broadcast traffic within subnetwork
Reduce overall network traffic and improve network performance
Communication Between Subnets
Each router interface must have an IPv4 host address that belongs to the network or subnet that the router interface is connected to
Devices on a network and subnet use the router interface attached to their LAN as their default gateway.
A router is necessary for devices on different networks and subnets to communicate.
Subnetting Based on Host Requirements
There are two considerations when planning subnets
Number of Host addresses required
Formula to determine number of useable hosts
2^n-2
2^n (where n is the number the number of host bits remaining) is
used to calculate the number of hosts
-2 Subnetwork ID and broadcast address cannot be used on each
subnet
Number of Subnets required
Subnetting To Meet Network Requirements
Design the addressing scheme to accommodate the
maximum number of hosts for each subnet.
Allow for growth in each subnet.
It is important to balance the number of subnets needed
and the number of hosts required for the largest subnet
Traditional Subnetting Wastes Addresses
Variable Length Subnet Mask (VLSM) or subnetting a
subnet provides more efficient use of addresses.
Traditional subnetting - same number of addresses is
allocated for each subnet.
Subnets that require fewer addresses have unused
(wasted) addresses. For example, WAN links only need 2 addresses
Planning to Address the Network
Allocation of network addresses should be planned and
documented for the purposes of
Providing and controlling access
Monitoring security and performance
Preventing duplication of addresses
Addresses for Clients - usually dynamically assigned using
Dynamic Host Configuration Protocol (DHCP)
Subnetting Using the Subnet ID
An IPv6 Network Space is subnetted to support hierarchical, logical design of the network
Subnetting into the Interface ID
IPv6 bits can be borrowed from the interface ID to create
additional IPv6 subnets