© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public ITE PC v4.0 Chapter 1 1 Network Addressing Networking for Home and Small Businesses – Chapter 5

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Purpose of an IP Address  A logical network address that identifies a host  A host (end-user) must have a NIC card – workstations – servers – printers – router interface  Each packet will contain a source and destination IP address Packet Tracer Activity Cisco I

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public IP addresses  IP Version 4 – most common form of IP addresses  32 binary digits  4 octets  Dotted decimal notation  Over 4 billion possible IP addresses  IP Version 6 will soon become the standard to ensure we have enough addresses to use

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Binary Numbers  The IP address is made up of binary numbers (1 or 0)  Humans must be able to talk computer language to send data  We do this by converting our numbering system (Base 10 to binary)  Let’s try some... Convert 140 to binary Convert 10 to binary Convert to Base 10 Convert to Base 10 Time to play a game -- Online Activity

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Parts of an IP Address  Hierarchical – made up of 2 parts network host(Id’s the specific device) – determined by IP class  Similar to your phone number – Area code = network – phone number = host(specific location)  Go to page to see how network addresses are used

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Purpose of the Subnet Mask  Helps identify the network  Boolean math or “ANDING”  What happens if both source and destination IP are on the same network?? What happens if they are not??

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Copy Into Your Notes  On page copy the chart of IP Address Classes

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Types of IP Addresses  Class A – Range – N.H.H.H – First bit in octet will be a 0 – Default subnet mask – can create over 16 million host addresses – the most host addresses available in networking 2 24 – 2 = 16,777,214 to be exact why do you subtract 2??? – Used in large organizations

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Types of IP Addresses  Class B – Range – N.N.H.H – 16 bits for network and 16 bits for host – Default subnet mask – can create over 65,000 host addresses 2 16 – 2 = 65,534 to be exact – Used in medium-sized organizations

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Types of IP Addresses  Class C – Range – N.N.N.H – First two bits in octet will be a 11 – Default subnet mask – can create 254 useable hosts 2 8 – 2 = 254 to be exact – Used in small organizations

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Types of IP Addresses  Class D – Range – used for multicasting – not for commercial use  Class E – Range – reserved for experimental use – not for commercial use

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Activity  On page use the activity to test your skills looking at IP addresses and determining their default subnet mask.

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Private IP Addresses  Solves the issue of a finite number of available public IP addresses  Allows hosts to communicate locally without each device needing a public IP address  Not routed on the Internet; blocked by the ISP router  Private address ranges  Class A –  Class B – –  Class C – –

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Activity  On page can you determine which addresses are private and need to be blocked and which addresses are public and need to be passed through the router?

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Unicast Address  Most common type of address  Intended for a specific host, has a specific IP Address  Talking to a person on the phone is an example  Must have both destination IP and MAC in the header

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Broadcast Address  All ones in the host portion of the IP address – Class C address: (N.N.N.H) – Broadcast address:  MAC address all Fs – FF-FF-FF-FF-FF-FF

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Multicast Address  Send packet to a group of devices  Must use multicast address range  Range –  Used for remote gaming  Destination MAC address begins with: – E

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Activity  On page can you determine who the message will go to based on the address. Is the message a uni- cast, multicast or broadcast. Think back to how we identified these items on the last few slides.

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Using Static IP Addressing  Manually configured by the network administrator  Advantages – useful for printers, servers, etc – increased control of resources (security)  Disadvantages – time consuming

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Using Dynamic IP Addressing  Automatic assignment of IP addresses  Useful if frequent change in users (wireless hotspot)  Uses DHCP (Dynamic Host Configuration Protocol) server  IP addresses leased for a period of time – if host is removed from the network (turned off), the IP address goes back into the pool of IP address  Preferred method for large networks – reduces the burden of network support

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public DHCP  DHCP dynamically assigns an IP address to a host  A PC obtains its IP address from a DHCP server. If the PC is taken off the network for repair, what happens to the IP address configuration? The addresses is returned to the pool for reuse when the lease expires.

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Configuring DHCP  If host is configured as DHCP client, it will not have a – IP address – Subnet Mask – Default Gateway  Clients send a DHCP Discover Message –The message comes from a client seeking an IP address –The destination IP address of the message is – All hosts receive the message, but only a DHCP server replies

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Obtaining an IP address from DHCP server  Multifunction device (Linksys Router) provides services to clients (SOHO network)  If a host connects to a Linksys integrated router that is also a DHCP server and receives an IP address from it. Which address does the host need to access the ISP and the Internet? - Internal IP address of the integrated router that connects to the local network

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Packet Tracer  Configure a DHCP Server within a network. Open packet tracer and open the file Cisco I and follow the instructions for successful completion.

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Purpose of a Gateway  Used by the router to provide the path through which hosts on one network can communicate with hosts on a different network  Default gateway address – IP address of the router interface  If DHCP is being used – the DHCP server will automatically send the correct IP interface to the host to use as the default gateway

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Address Assignment  ISR (Integrated Services Router)  Default IP address – Class C Private Address – Configured on router interface  Internal hosts must be assigned addresses within the same network

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Address Management  Direct Connection – direct connection from PC to ISP through modem – public address assigned to the host  Connection through Integrated Router – more than one host needs access to the Internet – modem connected to ISR  Connection through Gateway Device – ISR and modem in one unit – connect directly to ISP

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Using NAT with a Home or Small Business Network  NAT (Network Address Translation)  Packets that stay local are not translated using NAT  Only packets destined for different network use NAT  NAT Prevents external users from detecting the IP addresses used on a network  With NAT, a private (local) source IP address is translated to a public (global) address. The process is reversed for incoming packets.

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public  Refer to the graphic. NAT and DHCP are installed on the Linksys integrated router. Which IP address is most likely to be assigned to the local computer, Host1?  Why would this address be chosen? because it is the only private IP address within the range.

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public Chapter Quiz  Take the chapter 5 quiz found on page to test your knowledge over IP addresses and the uses of the address in most networks around the world.

© 2007 Cisco Systems, Inc. All rights reserved.Cisco Public