- Network+ Guide to Networks6th Edi

- Network+ Guide to Networks
6th Edition
- Chapter 4
- Introduction to TCP/IP Protocols
- Objectives
- Identify and explain the functions of the core TCP/IP protocols
- Explain the TCP/IP model and how it corresponds to the OSI model
- Discuss addressing schemes for TCP/IP in IPv4 and IPv6 and explain how addresses are assigned automatically using DHCP (Dynamic Host Configuration Protocol)
- Objectives (cont’d.)
- Describe the purpose and implementation of DNS (Domain Name System)
- Identify the well-known ports for key TCP/IP services
- Describe how common Application layer TCP/IP protocols are used
- Characteristics of TCP/IP (Transmission Control Protocol/Internet Protocol)
- TCP/IP is a suite of protocols
- Referred to as “IP” or “TCP/IP”
- Subprotocols include TCP, IP, UDP, ARP, etc.
- Developed by US Department of Defense
- ARPANET (1960s)
- Internet precursor
- Characteristics of TCP/IP (cont’d.)
- Advantages of TCP/IP
- Open nature (Open Source)
- Not owned by a company
- Costs nothing to use
- Flexible
- Runs on virtually any platform
- Connects dissimilar operating systems and devices
- Routable
- Transmissions carry Network layer addressing information
- Suitable for large networks

- The TCP/IP Model
- Four layers
o 4) Application layer
o 3) Transport layer
o 2) Internet layer
- Network access layer (or Link layer)
- This model is sometimes considered more practical than the OSI model
- Understanding the model can help when you are troubleshooting network problems
- The TCP/IP Core Protocols
- TCP/IP core protocols
- Operate in Transport (layer 4) or Network (layer 3) of the OSI model
- Provide basic services to protocols in other layers
- Most significant protocols in TCP/IP suite
- TCP
- IP
- TCP (Transmission Control Protocol)
- Transport layer protocol
- Provides reliable data delivery services
- Connection-oriented subprotocol
- Establish connection before transmitting the data
- Determines if a host is offline
- Uses sequencing and checksums
- Provides flow control
- TCP segment format
- Encapsulated by IP packet in Network layer
- Becomes IP packet’s “data”
- TCP 3-Way Handshake
- 3-Way Handshake (SYN, SYN-ACK, ACK)
- How two computers negotiate and create a TCP socket connection
- Once the 3-way handshake it complete the date can be transmitted (socket has been created)
- When the transmission is complete another 3-way handshake is performed to tear down the TCP socket connection

- 3-Way Handshake (cont’d.)
- Host A sends a TCP SYNchronize packet to Host B
- Host B receives A's SYN
- Host B sends a SYNchronize-ACKnowledgement
- Host A receives B's SYN-ACK
- Host A sends ACKnowledge
- Host B receives ACK
- TCP socket connection is ESTABLISHED
- TCP (cont’d.)
- 3-Way Handshake
- Computer A issues message to Computer B
- Sends segment with SYN bits set
- SYN field: Random synchronize sequence number
- Computer B receives message
- Sends segment with SYN & ACK bits set
- SYN-ACK field: random number
- ACK field: Computer A’s sequence number plus 1
- TCP (cont’d.)
- Computer A responds
- Sends segment ACK bits set
- SYN field: Computer B random number
- ACK field: Computer B’s sequence number plus 1
- FIN flag indicates transmission end
- UDP (User Datagram Protocol)
- Transport layer protocol
- Provides unreliable data delivery services
- Connectionless transport service
- No assurance packets received in correct sequence
- No guarantee packets received at all
- No error checking, sequencing
- Lacks sophistication
- More efficient than TCP
- Useful situations
- Great volume of data transferred quickly
- Live audio or video
- IP (Internet Protocol)
- Network layer protocol of OSI
- Internet layer of the TCP/IP model
- How and where to deliver data, including:
- Data’s source and destination addresses
- Enables TCP/IP to internetwork
- Traverse more than one LAN segment and more than one network type through a router
- Network layer data formed into packets
- IP packet acts as an envelope for data and contains information necessary for routers to transfer data between different LAN segments
- IP (cont’d.)
- Two versions
- IPv4
- IPv6
- Newer version of IPv6
- IP next generation
- Released in 1998
- Advantages of IPv6
- Provides billions of additional IP addresses
- Better security and prioritization provisions
- IGMP (Internet Group Management Protocol)
- Operates at Network layer of OSI model
- Manages multicasting on networks running IPv4
- Multicasting
- Point-to-multipoint transmission method
- One node sends data to a group of nodes
- Used for Internet teleconferencing or videoconferencing
- Routers use IGMP to determine which nodes belong to a certain multicast group
- ARP (Address Resolution Protocol)
- Network layer protocol (Used with IPv4)
- Resolves IP addresses to MAC addresses
- Obtains MAC (physical) address of host or node
- Creates database that maps MAC to host’s IP address (arp cache)
- Used to minimize the number of ARP broadcasts
- ARP table
- Table of recognized MAC-to-IP address mappings
- Saved on computer’s hard disk
- Increases efficiency
- Contains dynamic and static entries
- ICMP (Internet Control Message Protocol)
- Network layer protocol
- Reports on data delivery success/failure
- Announces transmission failures to sender
- ICMP cannot correct errors
- Provides critical network problem troubleshooting information
- ICMPv6 used with IPv6
- Carry out the functions that ICMP, IGMP, and ARP perform in IPv4
- IPv4 Addressing
- Networks recognize two addresses
- Logical address (Network layer)
- Physical address (MAC, hardware)
- IP protocol handles logical addressing
- Specific parameters
- Unique 32-bit number
- Divided into four octets (sets of eight bits) separated by periods
- Example: 144.92.43.178
- Network class determined from first octet
- IPv4 Addressing (cont’d.)
- Class D, Class E rarely used (never assign)
- Class D: value between 224 and 239
- Multicasting
- Class E: value between 240 and 254
- Experimental use
- Eight bits have 256 combinations
- Networks use 1 through 254
- 0: reserved as placeholder
- 255: reserved for broadcast transmission
- IPv4 Addressing (cont’d.)
- Class A devices
- Share same first octet (bits 0-7)
- Network ID
- Host: second through fourth octets (bits 8-31)
- Class B devices
- Share same first two octet (bits 0-15)
- Host: second through fourth octets (bits 16-31)
- Class C devices
- Share same first three octet (bits 0-23)
- Host: second through fourth octets (bits 24-31)
- IPv4 Addressing (cont’d.)
- Loop back address
- First octet equals 127 (127.0.0.1)
- Any IPv4 address starting with 127 is a loopback address
- Loopback test
- Attempting to connect to own machine
- Powerful troubleshooting tool
- Windows XP, Vista, Windows 7
- ipconfig command
- Unix, Linux
- ifconfig command

- Binary and Dotted Decimal Notation
- Dotted decimal notation
- Common way of expressing IP addresses
- Decimal number between 0 and 255 represents each octet
- 256 possibilities -- 28
- Period (dot) separates each decimal
- Dotted decimal address has binary equivalent
- Convert each octet
- Remove decimal points
- Subnet Mask
- 32-bit number identifying a device’s subnet
- Informs the rest of the network about the network to which the device is attached
- Four octets (32 bits) / (4 bytes)
- Expressed in binary or dotted decimal notation
- Assigned same way as IP addresses
- Manually or automatically (via DHCP)
- Subnet Mask (cont’d.)
- IPv6 Addressing
- Composed of 128 bits
- Eight 16-bit fields separated by a colon
- Typically represented in hexadecimal numbers
- Separated by a colon
- Example: FE22:00FF:002D:0000:0000:0000:3012:CCE3
- Abbreviations for multiple fields with zero values:
- Eliminate leading zeros:
- Field 00FF can be abbreviated FF
- Field 0000 can be abbreviated 0
- FE22:FF:2D:0:0:0:3012:CCE3
- Substitution of multiple zeros (only perform once):
- Known as double colon
- FE22:FF:2D::3012:CCE3
- IPv6 Addressing (cont’d.)
- Unicast address
- Assigned to a workstation’s network adapter
- Multicast address
- Used for transmitting data to many different devices simultaneously
- Anycast address
- Transmission of a message sent to any one computer of a set of computers
- Assigned to routers and not designed to be assigned to hosts, such as servers or workstations
- Format Prefix: indicates the type of IPv6 address (FE80)
- Modern devices and operating systems can use both IPv4 and IPv6
- Using both on a network is know as a dual-stack approach
- Assigning IP Addresses
- Government-sponsored organizations dole out IP addresses to ISPs
- IANA, ICANN, RIRs
- Most companies and individuals obtain IP addresses from their ISP and not from the government’s higher authorities
- Every network node must have unique IP address
- Error message otherwise
- Assigning IP Addresses (cont’d.)
- Static IP address
- Manually assigned
- To change: modify client workstation TCP/IP properties
- Human error can cause duplication
- Dynamic IP address
- Assigned automatically
- Most common method
- Dynamic Host Configuration Protocol (DHCP)
- DHCP (Dynamic Host Configuration Protocol)
- Automatically assigns device a unique IP address
- Application layer protocol
- Reasons for implementing
- Reduce time and planning for IP address management
- Reduce potential for error in assigning IP addresses
- Enable users to move workstations and printers
- Make IP addressing transparent for mobile users
- DHCP (cont’d.)
- DHCP leasing process
- Device borrows (leases) an IP address while attached to network
- Lease time
- Determined when client obtains IP address at log on
- User may force lease termination
- DHCP service configuration
- Specify leased address range
- Configure lease duration
- Several steps to negotiate client’s first lease


- DHCP (cont’d.)
- Terminating a DHCP Lease
- Expire based on period established in server configuration
- Manually terminated at any time
- Client’s TCP/IP configuration
- Server’s DHCP configura

Kết quả (Việt) 1:

- Network+ Guide to Networks6th Edition- Chapter 4- Introduction to TCP/IP Protocols- Objectives- Identify and explain the functions of the core TCP/IP protocols- Explain the TCP/IP model and how it corresponds to the OSI model- Discuss addressing schemes for TCP/IP in IPv4 and IPv6 and explain how addresses are assigned automatically using DHCP (Dynamic Host Configuration Protocol)- Objectives (cont’d.)- Describe the purpose and implementation of DNS (Domain Name System)- Identify the well-known ports for key TCP/IP services- Describe how common Application layer TCP/IP protocols are used- Characteristics of TCP/IP (Transmission Control Protocol/Internet Protocol)- TCP/IP is a suite of protocols- Referred to as “IP” or “TCP/IP”- Subprotocols include TCP, IP, UDP, ARP, etc.- Developed by US Department of Defense- ARPANET (1960s)- Internet precursor- Characteristics of TCP/IP (cont’d.)- Advantages of TCP/IP- Open nature (Open Source)- Not owned by a company- Costs nothing to use- Flexible- Runs on virtually any platform- Connects dissimilar operating systems and devices- Routable- Transmissions carry Network layer addressing information- Suitable for large networks- The TCP/IP Model- Four layerso 4) Application layero 3) Transport layero 2) Internet layer- Network access layer (or Link layer)- This model is sometimes considered more practical than the OSI model- Understanding the model can help when you are troubleshooting network problems-Các giao thức TCP/IP Core-Giao thức cốt lõi TCP/IP-Hoạt động trong giao thông vận tải (lớp 4) hoặc mạng (lớp 3) trong mô hình OSI-Cung cấp các dịch vụ cơ bản để giao thức lớp khác-Đáng giao thức TCP/IP mật-TCP-IP-TCP (Transmission Control Protocol)-Vận tải lớp giao thức-Cung cấp dịch vụ giao hàng dữ liệu đáng tin cậy-Kết nối theo định hướng subprotocol-Thiết lập các kết nối trước khi truyền dữ liệu-Xác định nếu một máy chủ là offline-Sử dụng trình tự và khả-Cung cấp kiểm soát dòng chảy-Định dạng đoạn TCP-Đóng gói bằng IP gói trong mạng lớp-Trở thành IP gói "dữ liệu"-TCP 3 chiều bắt tay-Bắt tay 3 chiều (SYN, SYN-ACK, ACK)-Làm thế nào hai máy tính thương lượng và tạo ra một kết nối TCP ổ cắm-Một khi bắt tay 3-cách nó hoàn thành ngày có thể được truyền (ổ cắm đã được tạo ra)-Khi truyền xong một 3-way bắt tay được thực hiện để xé xuống các ổ cắm kết nối TCP-Bắt tay 3 chiều (cont 'd)-Host A sẽ gửi một gói TCP đồng bộ hóa với máy chủ lưu trữ B-Host B nhận được của một SYN-Host B sẽ gửi một lời cảm ơn đồng bộ hóa-Host A nhận được của B SYN-ACK-Host A gửi ACKnowledge-Nhận được host B ACK-TCP ổ cắm kết nối được thiết lập-TCP (cont 'd)-Bắt tay 3 chiều-Thông báo vấn đề máy tính A đến máy tính B-Gửi các phân đoạn với SYN bit thiết lập-SYN lĩnh vực: ngẫu nhiên đồng bộ hóa chuỗi số-Máy tính B nhận được tin nhắn-Gửi các phân đoạn với SYN & ACK bit thiết lập- SYN-ACK field: random number- ACK field: Computer A’s sequence number plus 1- TCP (cont’d.)- Computer A responds- Sends segment ACK bits set- SYN field: Computer B random number- ACK field: Computer B’s sequence number plus 1- FIN flag indicates transmission end- UDP (User Datagram Protocol)- Transport layer protocol- Provides unreliable data delivery services- Connectionless transport service- No assurance packets received in correct sequence- No guarantee packets received at all- No error checking, sequencing- Lacks sophistication- More efficient than TCP- Useful situations- Great volume of data transferred quickly- Live audio or video- IP (Internet Protocol)- Network layer protocol of OSI- Internet layer of the TCP/IP model- How and where to deliver data, including:- Data’s source and destination addresses- Enables TCP/IP to internetwork- Traverse more than one LAN segment and more than one network type through a router- Network layer data formed into packets- IP packet acts as an envelope for data and contains information necessary for routers to transfer data between different LAN segments- IP (cont’d.)- Two versions- IPv4- IPv6- Newer version of IPv6- IP next generation- Released in 1998- Advantages of IPv6- Provides billions of additional IP addresses- Better security and prioritization provisions- IGMP (Internet Group Management Protocol)- Operates at Network layer of OSI model- Manages multicasting on networks running IPv4- Multicasting- Point-to-multipoint transmission method- One node sends data to a group of nodes- Used for Internet teleconferencing or videoconferencing- Routers use IGMP to determine which nodes belong to a certain multicast group- ARP (Address Resolution Protocol)- Network layer protocol (Used with IPv4)- Resolves IP addresses to MAC addresses- Obtains MAC (physical) address of host or node- Creates database that maps MAC to host’s IP address (arp cache)- Used to minimize the number of ARP broadcasts- ARP table- Table of recognized MAC-to-IP address mappings- Saved on computer’s hard disk- Increases efficiency- Contains dynamic and static entries- ICMP (Internet Control Message Protocol)- Network layer protocol- Reports on data delivery success/failure- Announces transmission failures to sender- ICMP cannot correct errors- Provides critical network problem troubleshooting information- ICMPv6 used with IPv6- Carry out the functions that ICMP, IGMP, and ARP perform in IPv4- IPv4 Addressing- Networks recognize two addresses- Logical address (Network layer)- Physical address (MAC, hardware)- IP protocol handles logical addressing- Specific parameters- Unique 32-bit number- Divided into four octets (sets of eight bits) separated by periods- Example: 144.92.43.178- Network class determined from first octet- IPv4 Addressing (cont’d.)- Class D, Class E rarely used (never assign)- Class D: value between 224 and 239- Multicasting- Class E: value between 240 and 254- Experimental use- Eight bits have 256 combinations- Networks use 1 through 254- 0: reserved as placeholder- 255: reserved for broadcast transmission- IPv4 Addressing (cont’d.)- Class A devices- Share same first octet (bits 0-7)- Network ID- Host: second through fourth octets (bits 8-31)- Class B devices- Share same first two octet (bits 0-15)- Host: second through fourth octets (bits 16-31)- Class C devices- Share same first three octet (bits 0-23)- Host: second through fourth octets (bits 24-31)- IPv4 Addressing (cont’d.)- Loop back address- First octet equals 127 (127.0.0.1)- Any IPv4 address starting with 127 is a loopback address- Loopback test- Attempting to connect to own machine- Powerful troubleshooting tool- Windows XP, Vista, Windows 7- ipconfig command- Unix, Linux- ifconfig command- Binary and Dotted Decimal Notation- Dotted decimal notation- Common way of expressing IP addresses- Decimal number between 0 and 255 represents each octet- 256 possibilities -- 28 - Period (dot) separates each decimal- Dotted decimal address has binary equivalent- Convert each octet- Remove decimal points- Subnet Mask- 32-bit number identifying a device’s subnet- Informs the rest of the network about the network to which the device is attached- Four octets (32 bits) / (4 bytes)- Expressed in binary or dotted decimal notation
- Assigned same way as IP addresses
- Manually or automatically (via DHCP)
- Subnet Mask (cont’d.)
- IPv6 Addressing
- Composed of 128 bits
- Eight 16-bit fields separated by a colon
- Typically represented in hexadecimal numbers
- Separated by a colon
- Example: FE22:00FF:002D:0000:0000:0000:3012:CCE3
- Abbreviations for multiple fields with zero values:
- Eliminate leading zeros:
- Field 00FF can be abbreviated FF
- Field 0000 can be abbreviated 0
- FE22:FF:2D:0:0:0:3012:CCE3
- Substitution of multiple zeros (only perform once):
- Known as double colon
- FE22:FF:2D::3012:CCE3
- IPv6 Addressing (cont’d.)
- Unicast address
- Assigned to a workstation’s network adapter
- Multicast address
- Used for transmitting data to many different devices simultaneously
- Anycast address
- Transmission of a message sent to any one computer of a set of computers
- Assigned to routers and not designed to be assigned to hosts, such as servers or workstations
- Format Prefix: indicates the type of IPv6 address (FE80)
- Modern devices and operating systems can use both IPv4 and IPv6
- Using both on a network is know as a dual-stack approach
- Assigning IP Addresses
- Government-sponsored organizations dole out IP addresses to ISPs
- IANA, ICANN, RIRs
- Most companies and individuals obtain IP addresses from their ISP and not from the government’s higher authorities
- Every network node must have unique IP address
- Error message otherwise
- Assigning IP Addresses (cont’d.)
- Static IP address
- Manually assigned
- To change: modify client workstation TCP/IP properties
- Human error can cause duplication
- Dynamic IP address
- Assigned automatically
- Most common method
- Dynamic Host Configuration Protocol (DHCP)
- DHCP (Dynamic Host Configuration Protocol)
- Automatically assigns device a unique IP address
- Application layer protocol
- Reasons for implementing
- Reduce time and planning for IP address management
- Reduce potential for error in assigning IP addresses
- Enable users to move workstations and printers
- Make IP addressing transparent for mobile users
- DHCP (cont’d.)
- DHCP leasing process
- Device borrows (leases) an IP address while attached to network
- Lease time
- Determined when client obtains IP address at log on
- User may force lease termination
- DHCP service configuration
- Specify leased address range
- Configure lease duration
- Several steps to negotiate client’s first lease


- DHCP (cont’d.)
- Terminating a DHCP Lease
- Expire based on period established in server configuration
- Manually terminated at any time
- Client’s TCP/IP configuration
- Server’s DHCP configura