11 ASSIGNING IP ADDRESSES Chapter 2

Chapter 2: ASSIGNING IP ADDRESSES2 CHAPTER OVERVIEW  Describe the structure of IP addresses and subnet masks.  Specify which computers on a network should use public addresses and which should use private addresses.  Calculate IP addresses and subnet masks for subnetted networks.  List the drawbacks of manual TCP/IP client configuration.  Understand how DHCP automatically configures TCP/IP clients.  Describe the structure of IP addresses and subnet masks.  Specify which computers on a network should use public addresses and which should use private addresses.  Calculate IP addresses and subnet masks for subnetted networks.  List the drawbacks of manual TCP/IP client configuration.  Understand how DHCP automatically configures TCP/IP clients.

Chapter 2: ASSIGNING IP ADDRESSES3 UNDERSTANDING IP ADDRESSING  A 32-bit binary value that is typically expressed as four 8-bit decimal numbers, separated by periods, as in

Chapter 2: ASSIGNING IP ADDRESSES4 IP ADDRESS COMPONENTS  Network ID—Defines the IP address of the network that the host is on  Host ID—Defines the address of that host on the network  Network ID—Defines the IP address of the network that the host is on  Host ID—Defines the address of that host on the network

Chapter 2: ASSIGNING IP ADDRESSES5 NETWORK IDENTIFIERS

Chapter 2: ASSIGNING IP ADDRESSES6 HOST IDENTIFIERS  Each system on the same network must have a unique host identifier.  Two systems on two different networks can have the same host identifiers.  Duplicate host identifiers will disable at least one of the systems.  Each system on the same network must have a unique host identifier.  Two systems on two different networks can have the same host identifiers.  Duplicate host identifiers will disable at least one of the systems.

Chapter 2: ASSIGNING IP ADDRESSES7 UNDERSTANDING SUBNET MASKS  Defines which bits of the IP address refer to the network ID and which bits refer to the host ID.  A binary value of 1 determines that the bit in that location refers to the network ID.  A binary value of 0 determines that the bit in that location refers to the host ID.  Defines which bits of the IP address refer to the network ID and which bits refer to the host ID.  A binary value of 1 determines that the bit in that location refers to the network ID.  A binary value of 0 determines that the bit in that location refers to the host ID.

Chapter 2: ASSIGNING IP ADDRESSES8 UNDERSTANDING IP ADDRESS CLASSES

Chapter 2: ASSIGNING IP ADDRESSES9 DETERMINING IP ADDRESSING REQUIREMENTS  Registered  Can be used on the Internet  Assigned by the Internet Assigned Numbers Authority (IANA)  Unregistered  Can only be used on private networks  Can use any compliant numbering scheme  Registered  Can be used on the Internet  Assigned by the Internet Assigned Numbers Authority (IANA)  Unregistered  Can only be used on private networks  Can use any compliant numbering scheme

Chapter 2: ASSIGNING IP ADDRESSES10 PUBLIC AND PRIVATE NETWORKS  Public network—The Internet  Requires connected systems to use registered IP address  Private network—Any network that is not part of the Internet  Can use any IP addressing scheme  Public network—The Internet  Requires connected systems to use registered IP address  Private network—Any network that is not part of the Internet  Can use any IP addressing scheme

Chapter 2: ASSIGNING IP ADDRESSES11 USING REGISTERED ADDRESSES

Chapter 2: ASSIGNING IP ADDRESSES12 USING UNREGISTERED ADDRESSES Address Class Private Address Range Class A to Class B to Class C to

Chapter 2: ASSIGNING IP ADDRESSES13 PLANNING IP ADDRESSES  Systems with connection to the Internet require a registered IP address.  Systems that connect to the Internet indirectly can use unregistered IP addresses and a system such as NAT or a proxy server to gain Internet access.  Each segment on the network requires a unique network address.  Systems with connection to the Internet require a registered IP address.  Systems that connect to the Internet indirectly can use unregistered IP addresses and a system such as NAT or a proxy server to gain Internet access.  Each segment on the network requires a unique network address.

Chapter 2: ASSIGNING IP ADDRESSES14 OBTAINING NETWORK ADDRESSES  Network addresses are normally obtained from your ISP.  For a small number of systems, ask for a group of addresses on the same subnet.  For a large number of systems, obtain a network address with sufficient host IDs.  Network addresses are normally obtained from your ISP.  For a small number of systems, ask for a group of addresses on the same subnet.  For a large number of systems, obtain a network address with sufficient host IDs.

Chapter 2: ASSIGNING IP ADDRESSES15 SUBNETTING IP ADDRESSES  What is subnetting?  The process of creating individual network addresses out of a larger network address  What is subnetting?  The process of creating individual network addresses out of a larger network address

Chapter 2: ASSIGNING IP ADDRESSES16 UNDERSTANDING SUBNETTING

Chapter 2: ASSIGNING IP ADDRESSES17 SUBNETTING BETWEEN BYTES  Uses a single octet to express both the network and node addresses  Results in a single decimal which reflects the network and node addresses  Uses a single octet to express both the network and node addresses  Results in a single decimal which reflects the network and node addresses

Chapter 2: ASSIGNING IP ADDRESSES18 CALCULATING IP ADDRESSES USING THE BINARY METHOD

Chapter 2: ASSIGNING IP ADDRESSES19 CONVERTING BINARIES AND DECIMALS

Chapter 2: ASSIGNING IP ADDRESSES20 CALCULATING A SUBNET MASK  The subnet mask value is determined by the subnetting process.  Subnet mask value can be expressed in dotted decimal or slash notation.  The subnet mask value is determined by the subnetting process.  Subnet mask value can be expressed in dotted decimal or slash notation.

Chapter 2: ASSIGNING IP ADDRESSES21 CALCULATING IP ADDRESSES USING THE SUBTRACTION METHOD  Take the decimal value of the quad in the subnet mask that contains both subnet and host identifier bits and subtract it from 256.  Repeatedly increment that result by the remainder from the step above. The result of each addition forms a subnet address.  Take the decimal value of the quad in the subnet mask that contains both subnet and host identifier bits and subtract it from 256.  Repeatedly increment that result by the remainder from the step above. The result of each addition forms a subnet address.

Chapter 2: ASSIGNING IP ADDRESSES22 DEPLOYING IP ADDRESSES  Manual configuration  Installation answer file  DHCP  Manual configuration  Installation answer file  DHCP

Chapter 2: ASSIGNING IP ADDRESSES23 CONFIGURING IP ADDRESSES MANUALLY

Chapter 2: ASSIGNING IP ADDRESSES24 USING ANSWER FILES  Each system requires a separate answer file.  One-off can be used only during installation of the operating system.  Relatively complex file structure requires testing and verification.  Each system requires a separate answer file.  One-off can be used only during installation of the operating system.  Relatively complex file structure requires testing and verification.

Chapter 2: ASSIGNING IP ADDRESSES25 DEPLOYING IP ADDRESSES USING DHCP  Automates IP address deployment  Allows for simple reconfiguration of IP addressing schemes  Eliminates human error in address assignment  Generates very little network traffic and requires minimal administration after initial setup and configuration  Automates IP address deployment  Allows for simple reconfiguration of IP addressing schemes  Eliminates human error in address assignment  Generates very little network traffic and requires minimal administration after initial setup and configuration

Chapter 2: ASSIGNING IP ADDRESSES26 UNDERSTANDING DHCP ALLOCATION METHODS  Dynamic  Automatic  Manual  Dynamic  Automatic  Manual

Chapter 2: ASSIGNING IP ADDRESSES27 INSTALLING AND CONFIGURING A DHCP SERVER

Chapter 2: ASSIGNING IP ADDRESSES28 DEPLOYING DHCP CLIENTS

Chapter 2: ASSIGNING IP ADDRESSES29 UNDERSTANDING DHCP CLIENT/SERVER COMMUNICATIONS

Chapter 2: ASSIGNING IP ADDRESSES30 PLANNING A DHCP DEPLOYMENT  DHCP packets are broadcasts and are not forwarded by routers.  DHCP Relay agents forward DHCP requests.  Relay agents allow a single DHCP server to service the entire internetwork.  DHCP packets are broadcasts and are not forwarded by routers.  DHCP Relay agents forward DHCP requests.  Relay agents allow a single DHCP server to service the entire internetwork.

Chapter 2: ASSIGNING IP ADDRESSES31 DEPLOYING MULTIPLE DHCP SERVERS  Provides fault tolerance.  Must not have duplicate scopes.  Microsoft recommends the 80:20 rule.  Provides fault tolerance.  Must not have duplicate scopes.  Microsoft recommends the 80:20 rule.

Chapter 2: ASSIGNING IP ADDRESSES32 CHAPTER SUMMARY  Every computer on a TCP/IP network must have a unique IP address.  You can create subnets using any network address by using some of the host identifier bits to create a subnet identifier.  You can configure the TCP/IP clients on your network manually, or you can use DHCP servers to automatically allocate IP addresses and other configuration parameters to your computers as needed.  Every computer on a TCP/IP network must have a unique IP address.  You can create subnets using any network address by using some of the host identifier bits to create a subnet identifier.  You can configure the TCP/IP clients on your network manually, or you can use DHCP servers to automatically allocate IP addresses and other configuration parameters to your computers as needed.