Network Addressing

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Network Addressing

• Networking for Home Small Business

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Objectives
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Purpose of an IP Address

• Each host needs IP to communicate
• Assigned to the NIC
• Computers, network printer, router interfaces
• Remember
• Packet has source destination IP

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Everything is IP
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IP Address Facts

• Logical (not physical like MAC)
• IPv4
• 32 bits, 4 octets
• 8 bits in each octet
• 11111111.10101010.11001100.00100101
• Written in decimal
• 192.101.28.36
• Value in each octet from 0-255
• Thats a total of 256 numbers.

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Convert binary to decimal

• Add up the values of the binary 1s
• 128 64 32 16 8 4 2 1
• 1 0 0 1 1 1 0
  0
• 156
• 11100101
• 229

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Binary/Decimal Conversions

• Practice
• Binary Game
• Handout

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Parts of an IP Address

• Network portion
• Host portion
• Routers care about network portion
• 192.175.36.9

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Activity
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IP Subnet Mask

• Subnet Mask
• Helps router decide which network packet is on
• Helps show which part of IP is network host
• 32 bits
• 192.168.6.5 255.255.255.0
• Binary 1s - ID the network portion
• Binary 0s - ID the host portion

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What network are these on?
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How many hosts- Unsubnetted?

• SM helps tells us how many hosts are on that
  network
• 255.255.255.0
• Binary 0 identifies of hosts on that network
• How many total hosts can be in one octet?
• 256
• Subtract 2 for useable
• 00000000 (.0) is the network ID
• 11111111 (.255) is the broadcast address for a
  network

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Binary/Dec/Hex

• Hex MAC address
• 0-9, A-F (10-15)
• AB

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Handout Lab

• 5.1.4 Lab
• Homework

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Review

• Which version IP addresses are we dealing with?
• IPv4
• How many bits in an IP address?
• 32
• How many octets in an IP address?
• 4
• Which part of this address is the host portion?
  199.81.71.6
• 6

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Review

• Which network does this belong on? 201.14.6.5
  255.255.255.0
• 201.14.6.0 network
• How many total hosts can be on that network?
  Useable?
• 256
• 254, why?

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IP Classes Default SM

• Class A
• Large organizations
• 1-127
• Default SM 255.0.0.0
• One octet for network, 3 octets for hosts
• How many hosts available?
• 224 over 16 million
• 10.52.33.7
• N.H.H.H
• 255.0.0.0
• 120.111.99.87

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Class A Example

• 15.7.92.5 255.0.0.0
• 15 Class A
• Default SM for Class A 255.0.0.0
• Network portion of address 15.
• Host portion .7.92.5
• Network ID 15.0.0.0
• All zeros in the host portion
• Broadcast address 15.255.255.255
• All binary ones in the host portion

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IP Classes Default SM

• Class B
• Medium organizations
• 128-191
• Default SM 255.255.0.0
• Two octets for network, 2 octets for hosts
• How many hosts available?
• 216 over 65,000
• 130.52.33.7
• N.N.H.H
• 255.255.0.0
• 185.111.99.87

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Class B Example

• 167.101.52.36 255.255.0.0
• 167 Class B
• Default SM for Class B 255.255.0.0
• Network portion of address 167.101
• Host portion .52.36
• Network ID 167.101.0.0
• All zeros in the host portion
• Broadcast address 167.101.255.255
• All binary ones in the host portion

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IP Classes Default SM

• Class C
• Small organizations
• 192-223
• Default SM 255.255.255.0
• Three octets for network, 1 octet for hosts
• How many hosts available?
• 28 256-2 (254 useable)
• 199.52.33.7
• N.N.N.H
• 255.255.255.0
• 220.111.99.87

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Class C Example

• 210.44.200.89 255.255.255.0
• 210 Class C
• Default SM for Class C 255.255.255.0
• Network portion of address 210.44.200
• Host portion .89
• Network ID 210.44.200.0
• All zeros in the host portion
• Broadcast address 210.44.200.255
• All binary ones in the host portion

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Other IP Classes More

• Class D E not for commercial use
• D is multicast (one to a group)
• 224.0.0.0- 239.255.255.255
• All 0s in host portion(s) network ID
• All 1s in host portion(s) broadcast
• CAN NOT USE THOSE FOR HOSTS!
• Activity on 5.2.1

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Handouts

• Lots of Practice!

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Public/Private IPs

• 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

Address Class Address Range
A 10.0.0.0- 10.255.255.255
B 172.16.0.0- 172.31.255.255
C 192.168.0.0- 192.168.255.255
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Private IPs

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

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Private Nets- 5.2.2 Activity
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Unicast Communication

• One-to-one or Source to destination

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Broadcast Communication

• One-to-all or Source to all in segment
• All hosts will look at it
• All 1s in host portion(s) of address
• Broadcast IP MAC
• Default Broadcasts
• A- 10.255.255.255 255.0.0.0
• B- 172.16.255.255 255.255.0.0
• C- 192.168.1.255 255.255.255.0

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Broadcast Communication
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Multicast Communication

• One-to-group
• Class D 224.0.0.0- 239.255.255.255
• Multicast MAC begins with 01-00-5E
• Where is it used?
• Gaming
• Distance learning

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Multicast Communication
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Which one?

• Unicast
• Multicast
• Broadcast

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Activity Handout

• 5.2.3.4
• Handout
• DOS
• Netstat e
• Do this every 10 seconds
• Pay attention to non-unicast packets

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Review

• 160.50.23.6 255.255.0.0 What network is this on?
• 160.50.0.0
• Which default SM has the most hosts?
• Class A 255.0.0.0
• Over 16 million!
• How many useable hosts in a Class C?
• 254
• 220.101.5.90 255.255.255.0 What network is this
  on?
• 220.101.5.0

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Review

• What are the private IP addresses?
• 10, 172.16-172.31, 192.168.
• What is the MAC broadcast frame in hex?
• FF-FF-FF-FF-FF-FF
• What is the MAC for a multicast?
• 01-00-5E
• One to one communication is
• Unicast
• To send a unicast message, which addresses do you
  need?
• Source dest. IP MAC

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Assigning IP Addresses

• Static
• Manually type in IP Address
• Good for printers or servers
• Devices people access all the time
• You wouldnt want their address changing!
• Good documentation!!!!

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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

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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

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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

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How DHCP Works
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Configuring DHCP on Linksys

• 192.168.1.1
• Packet
• Tracer Lab
• 5.3.3.3

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Review

• Which addresses does a host use to discover a
  DHCP server?
• 255.255.255.255
• FF-FF-FF-FF-FF-FF
• Who sees that? Who responds?
• All on the segment
• The DHCP server
• What happens to a PCs IP when you shut down?
• Goes back to the DHCP pool of addresses

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Network Boundaries
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The Network In Out
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How to Connect to the ISP

• Directly
• 1 PC to a modem
• PC gets address from ISP
• ISR
• Modem to ISR
• Internal PCs get addresses from ISR
• Gateway Device
• ISR Modem in one
• Internal gets private IPs

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NAT

• Translates private into public addresses
• Prevents external from seeing internal
• 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.

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NAT Example
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Packet Tracer

• 5.4.3.2

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Review

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

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Review
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Review
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Review
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Review
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Review
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Review
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Network Addressing

• Networking for Home Small Business