Fundamentals of Networking Discovery 1, Chapter 5 Network Addressing

Objectives Describe the purpose of an IP Address and Subnet Mask and how they are used on the Internet Describe the types of IP Addresses available Describe the methods of obtaining an IP Address Describe the use of NAT on a home or small business network using an ISR

Purpose of an IP Address Each host needs IP to communicate Logical address Assigned to the NIC ▫ Computers, network printer, router interfaces Remember ▫ Packet has source & destination IP

Everything is IP Complete Packet Tracer “Connecting to a Web Server Using IP”

IP Address Facts Logical (not physical like MAC) IPv4 32 bits, 4 octets ▫ 8 bits in each octet ▫ Written in decimal ▫ Value in each octet from ▫ That’s a total of 256 numbers.

Convert binary to decimal Add up the values of the binary 1’s ▫ ▫ 229

Binary/Decimal Conversions How to Do Conversions Handout Binary & Decimal Conversions Practice Binary Game in Curriculum

Review

Parts of an IP Address Network portion ▫ Identifies network to the router ▫ Router cares about this part Host portion ▫ Identifies the specific host ▫ Router doesn’t care about this part  Hierarchical Addressing

Activity

IP & Subnet Mask Interaction Subnet Mask ▫ Helps router decide which network packet is on ▫ Helps show which part of IP is network & host ▫ 32 bits ▫ Binary 1’s - ID the network portion Binary 0’s - ID the host portion

What network are these on? ANDing

ANDing- What network? What network does this belong to?

Review

How many hosts? Unsubnetted SM helps tells us how many hosts are on that network ▫ ▫ Binary 0= identifies # of hosts on that network ▫ 8 ZEROS is 2 8 =256 ▫ Subtract 2 for useable number  Unusable:  (.0) is the network ID  (.255) is the broadcast address for a network  Total Useable is 254

How many total & useable hosts? SM ▫ 128= ▫ 2 7 = is 126 hosts SM ▫ 224= ▫ 2 5 = 32-2 is 30 hosts SM ▫.240.0= ▫ 2 12 = is 4094 hosts

Figure It Out One PC is ▫ What is network does it belong to? ▫ How many useable hosts? ▫ Give PC’s addresses.

Binary/Dec/Hex Hex= MAC address 0-9, A-F (10-15) AB

Handout & Lab Lab (No Calculator) Homework- Decimal/Hex/Binary Conversion

Review 1.Which version IP addresses are we dealing with? ▫ IPv4 2.How many bits in an IP address? ▫ 32 3.How many octets in an IP address? ▫4▫4 4.Which part of this address is the host portion? ▫6▫6

Review 1.Which network does this belong on? ▫ network 2.How many total hosts can be on that network? Useable? ▫ 256 ▫ 254, why?

IP Classes & Default SM Class A ▫ Large organizations ▫ ▫ Default SM=  One octet for network, 3 octets for hosts ▫ How many hosts available?  2 24 = over 16 million ▫ ▫ N.H.H.H ▫ ▫

Class A Example = Class A Default SM for Class A= Network portion of address= 15. Host portion= Network ID= ▫ All zero’s in the host portion Broadcast address= ▫ All binary one’s in the host portion

IP Classes & Default SM Class B ▫ Medium organizations ▫ ▫ Default SM=  Two octets for network, 2 octets for hosts ▫ How many hosts available?  2 16 = over 65,000 ▫ ▫ N.N.H.H ▫ ▫

Class B Example = Class B Default SM for Class B= Network portion of address= Host portion= Network ID= ▫ All zero’s in the host portion Broadcast address= ▫ All binary one’s in the host portion

IP Classes & Default SM Class C ▫ Small organizations ▫ ▫ Default SM=  Three octets for network, 1 octet for hosts ▫ How many hosts available?  2 8 = (254 useable) ▫ ▫ N.N.N.H ▫ ▫

Class C Example = Class C Default SM for Class C= Network portion of address= Host portion=.89 Network ID= ▫ All zero’s in the host portion Broadcast address= ▫ All binary one’s in the host portion

Other IP Classes & More Class D & E not for commercial use ▫ D is multicast (one to a group) ▫ All 0’s in host portion(s) = network ID All 1’s in host portion(s)= broadcast CAN NOT USE THOSE FOR HOSTS!

IP Cheat Sheet

Handouts Activity on Lots of Practice!

Public/Private IP’s Address Class Address Range A B C Some addresses are reserved & can not be routed across Internet You can have a public IP for network/servers & private for hosts inside ▫ Saves IP addresses

Private IP’s If host does not connect DIRECTLY to Internet, it can have a private IP Router BLOCKS private IP’s Great Security!!! ▫ Private IP’s can not be seen from Internet range is reserved for loopback testing

Private Nets Activity

Review

Unicast Address Communication One-to-one or Source to destination

Broadcast Address Communication One-to-all or Source to all in segment All hosts will look at it All 1’s in host portion(s) of address Broadcast IP & MAC (all F’s) Default Broadcasts ▫ A ▫ B ▫ C

Broadcast Address Communication

Multicast Address Communication One-to-group Class D Multicast MAC begins with E Where is it used? ▫ Gaming ▫ Distance learning

Multicast Communication

Which one, based on the MAC? Unicast, Multicast, or Broadcast

Activity & Handout Handout DOS ▫ Netstat –e ▫ Do this every 10 seconds ▫ Pay attention to non-unicast packets

Review ; What network is this on? ▫ Which default SM has the most hosts? ▫ Class A ▫ Over 16 million! 3.How many useable hosts in a Class C? ▫ ; What network is this on? ▫

Review 1.What are the private IP addresses? ▫ 10, , What is the MAC broadcast frame in hex? ▫ FF-FF-FF-FF-FF-FF 3.What is the MAC for a multicast? ▫ E 4.One to one communication is… ▫ Unicast 5.To send a unicast message, which addresses do you need? ▫ Source & dest. IP & MAC

Assigning IP Addresses Static ▫ Manually type in IP Address ▫ Good for printers or servers  Devices people access all the time  You wouldn’t want their address changing! ▫ Good documentation!!!!

Assigning IP Addresses Dynamic ▫ Assigned auto by DHCP server ▫ Assigns IP, SM, DG, more ▫ Good for larger networks or with mobile/new devices ▫ Leased addresses

Assigning IP Addresses Admins have a pool of IP addresses ▫ DHCP assigns from the pool SOHO routers usually have DHCP Medical field- ▫ Legal requirement ▫ Must track who is on machine ▫ DHCP server assigns & keeps log of users

DHCP Servers How you get on the net in a hotel, Starbucks, or BK Either dedicated server or mixed in another device ▫ From ISP or on your ISR

How DHCP Works

Configuring DHCP on Linksys Packet Tracer Lab

Review 1.Which addresses does a host use to discover a DHCP server? ▫ ▫ FF-FF-FF-FF-FF-FF 2.Who sees that? Who responds? ▫ All on the segment ▫ The DHCP server 3.What happens to a PC’s IP when you shut down? ▫ Goes back to the DHCP pool of addresses

Network Boundaries

The Network In & Out

How to Connect to the ISP Directly ▫ 1 PC to a modem ▫ PC gets address from ISP ISR ▫ Modem to ISR ▫ Internal PC’s get addresses from ISR Gateway Device ▫ ISR & Modem in one ▫ Internal gets private IP’s

How to Connect to the ISP

NAT Translates private into public addresses Prevents external from seeing internal

NAT Translation A private (local) source IP address is translated to a public (global) address. ▫ The process is reversed for incoming packets. ▫ The integrated router is able to translate many internal IP addresses to the same public address, by using NAT.

NAT Example

Packet Tracer

Review 1.Which address does the PC need to access the Internet? ▫ Default gateway address of the ISR 2.Which devices translates NAT? ▫ ISR

Review- 11 Questions

Advanced Review- 6 Questions

Network Addressing Networking for Home & Small Business