module 5: creating ipv4 address spaces. overview of ip communication subnetting overview subnetting...
TRANSCRIPT
Module 5: Creating IPv4 Address Spaces
Module 5: Creating IPv4 Address Spaces
• Overview of IP Communication
• Subnetting Overview
• Subnetting for Complex Networks
Lesson 1: Overview of IP Communication
• What Are the IPv4 Address Classes?
• What Is ARP?
• IPv4 Communication Within a Single Network
• IPv4 Communication Between Networks
• Demonstration: Using ARP
What Are the IPv4 Address Classes?
Class CSmall Network
Class BMedium Network
Class ALarge Network
Network ID Host ID
1 1 0
xw y z
Network ID Host ID
1 0
xw y z
Network ID
Host ID
0
xw y z
What Is ARP?
The ARP protocol:
•Resolves IPv4 addresses to MAC addresses
•Provides MAC addresses for IP frames
•Dynamically stores MAC addresses in the ARP cache
The ARP tool:
•Displays the ARP cache
•Removes entries from the ARP cache
•Adds static entries to the ARP cache
IPv4 Communication Within a Single Network
Computer BComputer BComputer AComputer A
IP: 192.168.55.23MAC: 00:43:D2:ED:1A:98
IP: 192.168.55.99MAC: 2C:33:85:C2:AA:32
Determine local or remote network
Resolve destination IP to MAC address
Address packet
Deliver packet to destination
11
22
33
44
IPv4 Communication Between Networks
IP: 192.168.55.23MAC: 00:43:D2:ED:1A:98
IP: 192.168.37.99MAC: 2C:33:85:C2:AA:32
IP: 192.168.55.1MAC: 6B:11:43:75:CB:11
IP: 192.168.37.1MAC: 6B:11:43:75:CB:12
Determine local or remote network
Resolve default gateway IP to MAC address
Address and deliver packet to default gateway
Resolve destination IP to MAC address
Address and deliver packet to destination
11
22
33
44
55
Computer BComputer BComputer AComputer A
Demonstration: Using ARP
In this demonstration, you will see how to use ARP
Lesson 2: Subnetting Overview
• How Dotted Decimal Notation Relates to Binary Numbers
• What Is a Subnet?
• How Bits Are Used in a Subnet Mask
• How the Computer Determines Whether an IP Address Is Local or Remote
How Dotted Decimal Notation Relates to Binary Numbers
Bit 7Bit 7 Bit 6Bit 6 Bit 5Bit 5 Bit 4Bit 4 Bit 3Bit 3 Bit 2Bit 2 Bit 1Bit 1 Bit 0Bit 0
8-Bit Octet
Decimal Value
128128 6464 3232 1616 88 44 22 11
27272626
25252424
23232222
21212020
What Is a Subnet?
Subnet 1131.107.10.0
Main Network131.107.12.0
Subnet 2131.107.3.0
131.107.10.12131.107.10.12
131.107.12.31131.107.12.31
131.107.3.27131.107.3.27
131.107.12.7131.107.12.7
RouterRouter
RouterRouter
How Bits Are Used in a Subnet Mask
Class B Address with SubnetClass B Address with Subnet
Number of Subnets 254
Number of Hosts 254
Network ID Host ID
1
Subnet ID
0
128643216842
65,5348,1284,0642,0321,01650816,25632,512
0254
254
How the Computer Determines Whether an IP Address Is Local or Remote
Local and destination hosts’ IP addresses are each ANDed with their subnet masks
10011111 11100000 00000000 00000000
10011111 11100000 00000111 10000001
11111111 11111111 00000000 00000000IP AddressSubnet MaskIP AddressSubnet Mask
ResultResult
1 AND 1 = 1
Other combinations = 0
If ANDed results of source and destination hosts match, the destination is local
Lesson 3: Subnetting for Complex Networks
• Determining the Number of Subnet Bits
• Determining the Number of Host Bits
• Calculating Network Addresses
• Demonstration: Subnetting
Determining the Number of Subnet Bits
You should:
• Choose the number of subnet bits based on the number of subnets required
• Use 2n to determine the number of subnets available from n bits
For five locations, three subnet bits are required
• 5 locations = 5 subnets required
• 22 = 4 subnets (not enough)
• 23 = 8 subnets
Determining the Number of Host Bits
You should:
• Choose the number of host bits based on the number of hosts required on each subnet
• Use 2n-2 to determine the number of hosts available on each subnet available from n bits
For subnets 100 hosts, seven host bits are required
• 26-2 = 62 hosts (not enough)
• 27-2 = 126 hosts
Calculating Network Addresses
To determine the Network IDs:
• 172.16.0.0 will be subnetted using three bits
• The subnet mask is 255.255.11100000.0
• The lowest value bit in the subnet mask is the network ID increment
The network IDs increment by 32
• 172.16.0.0
• 172.16.32.0
• 172.16.64.0
• 172.16.96.0
• 172.16.128.0
• 172.16.160.0
• 172.16.192.0
• 172.16.224.0
Demonstration: Subnetting
In this demonstration, you will see how to perform subnetting
Lab: Creating IPv4 Address Spaces
• Exercise 1: Defining the Subnet Mask for a WAN
• Exercise 2: Defining the Hosts for a Network
Estimated time: 60 minutes
Lab Review
• What is the value of the host bits for the network address?
• What is the value of the host bits for the broadcast address on a subnet?
Module Review and Takeaways
• Review Questions
• Real-world Issues and Scenarios
• Best Practices