© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 1 Addressing the network IPv4 CCNA Exploration Semester 1 – Chapter 6

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 2 IP addressing – works at  OSI model layer 3  TCP/IP model Internet layer Application Presentation Session Transport Network Data link Physical Application Transport Internet Network Access TCP, UDP IP Ethernet, WAN technologies HTTP, FTP, TFTP, SMTP etc Segment Packet Frame Bits Data stream

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 3 Addressing topics  Binary and decimal  Types of IP addresses  Assigning addresses  Network part and subnet masks  Calculating addresses  Ping and Traceroute Utilities

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 4 Binary and decimal  Convert to 8-bit binary  248  187  89  Convert to decimal   

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public to binary

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public to binary

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 7 89 to binary

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public to decimal

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public to decimal

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public to decimal

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 11 Binary and decimal  Convert to 8-bit binary     Convert to decimal   

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 12 IPv4 address octet network parthost part Prefix /24 Subnet mask:

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 13 Find the network address In a network address, all the host bits are The router needs to do this for every packet.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 14 Logical AND Do a logical AND at each position

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 15 Find the broadcast address In a broadcast address, all the host bits are The broadcast is the last address in the network.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 16 3 types of address  Every network has:  Network address – the first one  Broadcast address – the last one  Host addresses – everything in between

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 17 Classful addressing network parthost part A network parthost part B network parthost part C

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 18 Classful addressing  Easy to work out but very wasteful.  Routers and hosts still assume class subnet masks by default  Class A/  Class B/  Class C/

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 19 Classless addressing  Any suitable prefix can be used  We (and devices) need to know what the prefix is.  More flexible, less wasteful.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 20 Classless addressing /16  /16 mask  Broadcast address  Hosts to  host addresses

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 21 Classless addressing /24  /24 mask  Broadcast address  Hosts to  254 host addresses

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 22 Classless addressing /22  /22 mask  Broadcast address  Hosts to  1022 host addresses

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 23 Classless addressing /26  /22 mask  Broadcast address  Hosts to  62 host addresses

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 24 Classless addressing /28  /28 mask  Broadcast address  Hosts to  14 host addresses

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 25 Calculating addresses  A host has IP address /24  What is the subnet mask?  What is the network address?  What is the broadcast address?  What is the range of host addresses in the network?

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public /24 – fill in the table Last octet binaryLast octet decimal Full Host Subnet mask Network Broadcast First host Last host

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public /24 Last octet binaryLast octet decimal Full Host Subnet mask Network Broadcast First host Last host

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 28 Calculating addresses  A host has IP address /26  What is the subnet mask?  What is the network address?  What is the broadcast address?  What is the range of host addresses in the network?

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public /26 fill in the table Last octet binary Last octet decimal Full Host Subnet mask Network Broadcast First host Last host

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public /26 Last octet binary Last octet decimal Full Host Subnet mask Network Broadcast First host Last host

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 31 Calculating addresses  A host has IP address /28  What is the subnet mask?  What is the network address?  What is the broadcast address?  What is the range of host addresses in the network?

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public /28 fill in the table Last octet binary Last octet decimal Full Host Subnet mask Network Broadcast First host Last host

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public /28 Last octet binary Last octet decimal Full Host Subnet mask Network Broadcast First host Last host

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 34 Unicast, Multicast, Broadcast  Unicast – a message addressed to one host  Broadcast – a message addressed to all hosts on a network. Uses network’s broadcast address or locally  Multicast – a message addressed to a group of hosts. Uses an address starting

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 35 Private IP addresses  Unrestricted use on private networks. Not routed across the Internet.  – ( /8)  – ( /20)  – ( /24)

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 36 Public IP addresses  Routed over the Internet  Master holder is IANA  Assigned to regional registries and then to ISPs  ISPs allocate them to organisations and individual users  Use is strictly controlled as duplicate addresses are not allowed

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 37 Special addresses  “all addresses” in default route. Hosts cannot be given addresses starting 0.  is loopback. Hosts cannot be given addresses starting 127.  and higher – reserved for experimental purposes.  local only  to for teaching

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 38 Network address translation  A large number of hosts on a network use private addresses to communicate with each other.  The ISP allocates one or a few public addresses.  NAT allows the hosts to share the public addresses when they want to use the Internet

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 39 Addressing hosts  Static addressing – address is configured by an administrator  Servers, printers, routers, switches need static addresses  Dynamic addressing – address is allocated automatically by DHCP by leasing addresses from a pool  Dynamic addressing is best for workstations

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 40 Blocks of addresses UseAddress rangeSummary Network address /25 User hosts Servers /26 Peripherals /27 Network devices /27 Router Broadcast

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 41 Subnetting /24 Address Subnet mask Last octet binary Borrow 1 bit from host part, give it to network part, /25 Addresses Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 42 Subnetting /24 Borrow 2 bits from host part, give to network part, /26 Addresses Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 43 Subnetting /24 Borrow 3 bits from host part, give to network part, /27 Addresses Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 44 Subnetting /24 Borrow 4 bits from host part, give to network part, / Subnet mask And so on…

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 45 Subnetting /24  Every time you borrow another bit you: Double the number of subnets Halve the size of the subnets  Each subnet has a network address, a broadcast address, and everything in between is a host address.  Here are some ways of visualising the process.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 46 Subnetting /24 Bits borrowed No of networks Prefix/25/26/27/28/29/30 Bit value/ network size No of hosts Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 47 Address space  Make a spreadsheet or table with numbers 0 to 255  Link to show table Link to show table

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 48 Subnet chart

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 49 Subnetting  There are many subnet calculators, but you will not be able to use them in exams.  Start with the biggest subnet and work down to the smallest.  Make sure the subnets are valid sizes with valid subnet masks.  Make sure that there are no overlaps.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 50 Ping and traceroute  Ping sends an ICMP message. If all is well, the destination replies. If not, a router may reply to say the destination is unreachable, or the ping may time out.  Traceroute sends a series of messages so that each router along the path replies. You get a list of addresses of all the routers.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 51 IPv6  Development started in 1990s because of concerns about IPv4 addresses running out  A whole new protocol suite – not just layer 3  Uses 128-bit hierarchical addressing, written using hexadecimal  Simpler header  Integrated security – authentication, privacy  Quality of service mechanisms

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 52 Subnetting - visual CCNA Exploration Semester 1 Chapter 6

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 53 Prefix /24 Three octets in network part, last octet in host part. All possible numbers 0 – 255 in last octet belong in the same network. Network address yellow Broadcast address blue Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 54 Prefix /25 First bit of fourth octet taken into network part. For every bit taken, double number of networks, halve their size. Network address yellow Broadcast address blue Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 55 Prefix /26 2 bits of fourth octet taken into network part. For every bit taken, double number of networks, halve their size. Network address yellow Broadcast address blue Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 56 Prefix /27 3 bits of fourth octet taken into network part. For every bit taken, double number of networks, halve their size. Network address yellow Broadcast address blue Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 57 Prefix /28 4 bits of fourth octet taken into network part. For every bit taken, double number of networks, halve their size. Network address yellow Broadcast address blue Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 58 Prefix /29 5 bits of fourth octet taken into network part. For every bit taken, double number of networks, halve their size. Network address yellow Broadcast address blue Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 59 Prefix /30 6 bits of fourth octet taken into network part. For every bit taken, double number of networks, halve their size. Network address yellow Broadcast address blue Subnet mask

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 60 Variable length Networks do not need to be all the same size. /27 /26 /25

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 61 Summary  Hierarchical Design model addresses performance, scalability, maintainability & manageability issues.  Traffic Analysis is used to monitor network performance.  Hierarchical Design Model is composed of 3 layers: Access Distribution Core  Switches selected for each layer must meet the needs of each hierarchical layer as well as the needs of the business.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 62 Labs & Activities TypeDetail PT1.2.4Mandatory* Lab1.3.1Mandatory PT1.3.2Mandatory Lab1.3.3Review carefully * If no previous Packet Tracer experience, else strongly recommended

© 2006 Cisco Systems, Inc. All rights reserved.Cisco Public 63