Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 1 Lesson 6 Internet Protocol (IP) Addressing

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 2 Internet Protocol (IP) Addressing Unicast IP addresses Subnetting Public and private addresses Broadcast IP addresses Multicast IP addresses

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 3 Types of IP Addresses Unicast Assigned to a single network interface Used in one-to-one communications Broadcast Designed to be processed by every IP node on the same network segment Used in one-to-everyone communications Multicast One or multiple nodes can be listening on the same or different network segments. Used in one-to-many communications

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 4 Expressing IP Addresses w.x.y.zw.x.y.z 32 bits

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 5 An 8-bit Number

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 6 Unicast IP Addresses Internetwork addresses for IP interfaces that contains a network ID and a host ID Network ID Assigned to a logical or physical network segment All nodes on the same logical network share the same network ID The network ID must be unique to the internetwork. Host ID Identifies a node within a network segment Must be unique to the network segment

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 7 Structure of a Unicast IP Address Network IDHost ID

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 8 Internet Address Classes (Historical) Originally assigned to create: A small number of large networks (networks with a large amount of nodes) A moderate number of moderate-sized networks A large number of small networks Address classes no longer used on the Internet

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 9 Class A Address 0 Network IDHost ID Address ClassFirst Network IDLast Network IDNumber of Networks Class A

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 10 Class B Address 10 Network IDHost ID Address ClassFirst Network IDLast Network IDNumber of Networks Class B ,384

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 11 Class C Address 110 Network IDHost ID Address ClassFirst Network IDLast Network IDNumber of Networks Class C ,097,152

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 12 A Class B Network ID Before Subnetting Internet

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 13 A Class B Network ID After Subnetting Internet

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 14 The Subnet Mask 32-bit value “1” indicates that the bit is used for the network ID “0” indicates that the bit is used for the host ID Expressed in either dotted decimal or network prefix notation Subnet Mask Address Class Dotted Decimal Notation Class A Class B Class C

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 15 Network Prefix Notation for Subnet Masks Subnet bits must be chosen in a contiguous fashion from the host bits Network prefix notation expresses the total number of network bits /of bits in the network ID Subnet Mask Address Class Network Prefix Length Class A Class B Class C /8 /16 /24

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 16 Custom Subnet Masks Subnetting along octet boundaries Subnetting along non-octet boundaries Subnet Mask Address Class Dotted Decimal Notation Class A Class B or / or / or / or /20

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 17 Determining the Network ID To extract the Network ID, the IP Address is ANDed with the Subnet Mask 1 AND 1 = 1 All other combinations = IP Address Subnet Mask Result AND =

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 18 How to Subnet 1. Decide how many host bits you need for the proper balance between number of subnets and number of hosts per subnet. The number of subnets needed both now and in the future The maximum number of hosts needed on each subnet 2. Based on the number of host bits chosen, enumerate the subnetted network IDs, including the ranges of usable IP addresses for each subnetted network ID.

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 19 Subnetting Original Network IDOriginal Host ID subnets 32,766 hosts 256 subnets 254 hosts

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 20 Variable-Length Subnetting Subnetting is applied recursively to produce subnets of different sizes all derived from the same original network ID Differently sized subnets use different subnet masks, or variable-length subnet masks (VLSM)

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 21 VLSM for / / / / / / / / / / / / / / / / / / / / / /

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 22 Supernetting and CIDR Elimination of Internet address classes Inefficient allocation Too many routing table entries Address blocks assigned based on total number of needed addresses Address block is a single network ID Address block becomes single route in the routing tables of Internet routers

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 23 Public and Private Addresses Public addresses Assigned by IANA or local ISP Globally reachable on the Internet Illegal or overlapping addresses  Public addresses use inside an organization that is not connected to the Internet Private addresses Reserved by IANA No reachable on the Internet /8, /12, and /16

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 24 Automatic Private IP Addressing Automatically assigned when: Windows node is configured for automatic configuration Alternate configuration not specified /16 Used for single subnet small office/ home office (SOHO) configurations Not connected to the Internet

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 25 IP Broadcast Addresses Network broadcast Set all the host bits to 1 for a classful address Subnet broadcast Set all the host bits to 1 for a non-classful address All-subnets-directed broadcast Set all the original classful network ID host bits to 1 for a non-classful network Limited broadcast

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 26 IP Multicast Addresses Set of hosts listening for the traffic of a specific IP multicast address is called a host group Multicast IP address range is to ( /4)  The all-hosts multicast address  The all-routers multicast address

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 27 IP Multicast to Ethernet Multicast 8 bits16 bits24 bits32 bits 40 bits 48 bits IP Multicast Address Ethernet Multicast Address Low Order 23 Bits 01005E

Microsoft Windows Server 2003 TCP/IP Protocols and Services Technical Reference Slide: 28 Review Unicast IP addresses Subnetting Public and private addresses Broadcast IP addresses Multicast IP addresses