مبانی شبکه های کامپیوتری براساس TCP/IP ومروری بر CCNA اولین همایش دانشجویی IT – دانشگاه بیرجند

عنوان مطالب طرح شده در این جلسه : مبانی شبکه های کامپیوتری پروتکل TCP/IP تکنولوژی CISCO و مروری بر CCNA

مبانی شبکه های کامپیوتری First recorded description of the social interactions enabled through networking written by Licklider of MIT First book on packet switching theory published by Leonard Kleinrock at MIT Lawrence Roberts went to DARPA to develop the computer network concept and put together his plan for “ARPANET” 1966 First host computer connected at UCLA 1969 Network Working Group finished the initial Host-to-Host protocol, called the Network Control protocol 1970 Kahn organized large and successful demonstration of the ARPANET at the International Computer Communication Conference. It was the first public demonstration of this new network technology to the public 1972

مبانی شبکه های کامپیوتری The idea of open-architecture networking was first introduced by Kahn shortly after having arrived at DARPA in WHY? Many networks exist in the world, often with different hardware and software. People connected to one network often want to communication with people attached to a different one. WHAT DO? TCP/IP Reference Model define in 1974 by Cerf and Kahn It was first define. A later perspective is given in (Leiner et al., 1985) The design philosophy behind the model is discussed in (Clark, 1988)

مبانی شبکه های کامپیوتری LAN 1LAN 2 City 1City 2 Internetwork Protocol 1986 Incompatible Networks Gateway 1 Gateway 2 The roughly 100 protocols became available in the 1980's The Internet has grown to include some 5,000 networks in over three dozen countries, serving over 700,000 host computers used by over 4,000,000 people in the 1990.( , News, File Transfer, Remote Login) Network

Standardization (ISO,IEEE) OSI : Open System Interconnection (1990) OSI is Reference Model and Layered Communication. The U.S. government passed laws requiring vendors to support OSI software on their systems. TCP/IP: Transmission Control Protocol / Internet Protocol TCP/IP is an application protocol. TCP/IP is a protocol suit. TCP/IP is follow the OSI Model.

Classification of interconnected processors by scale 0.1 m Circuit board 1 m System 10 m Room 100 m Building 1 km Campus 10 km City 100 km Country 1000 km Continent km Planet Interprocessor Distance Processors Located in Same Data flow machine Multicomputer Local Area Network Metropolitan Area Network Wide Area Network The internet

OSI Reference Model Layer 7ApplicationInterface between network and application Telnet,www browser, Eudora Layer 6PresentationHow data is present JPEG, ASCII, EBCDIC Layer 5SessionKeeping data separate from different application Operating system,RPC Layer 4TransportReliable or unreliable delivery Multiplexing TCP UDP SPX Layer 3NetworkLogical addressing, which routers use for path determination IP IPX ICMP Layer 2Data LinkCombination of bit to bytes, and byte to frame Error detection IEEE HDLC - Frame Relay – PPP-ATM Layer 1PhysicalMoving of bits between devices EIA/TIA-232, V.35 – Ethernet – FDDI – RJ45

OSI Model Overview Application (Upper) Layers Session Presentation Application

OSI Model Overview Data Flow Layers Transport Layer Data Link Network Layer Physical Application (Upper) Layers Session Presentation Application

Role of Application Layers Telnet HTTP User Interface EXAMPLES Application

Telnet HTTP ASCII EBCDIC JPEG User Interface How data is presented Special processing such as encryption EXAMPLES Presentation Application Role of Application Layers

Telnet HTTP ASCII EBCDIC JPEG Keeping different applications’ data separate User Interface How data is presented Special processing such as encryption Operating System/ Application Access Scheduling/RPC EXAMPLES Session Presentation Application Role of Application Layers Page113

Keeping different applications’ data separate User Interface How data is presented Special processing such as encryption Telnet HTTP ASCII EBCDIC JPEG Operating System/ Application Access Scheduling/RPC Transport Layer Data Link Network Layer Physical EXAMPLES Session Presentation Application Role of Application Layers

Role of Data Flow Layers EIA/TIA-232 V.35 EXAMPLES Physical Move bits between devices Specifies voltage, wire speed and pin-out cables

802.3 / HDLC EIA/TIA-232 V.35 EXAMPLES Role of Data Flow Layers Data Link Physical Combines bits into bytes and bytes into frames Access to media using MAC address Error detection not correction Move bits between devices Specifies voltage, wire speed and pin-out cables

802.3 / HDLC EIA/TIA-232 V.35 IP IPX EXAMPLES Role of Data Flow Layers Network Data Link Physical Combines bits into bytes and bytes into frames Access to media using MAC address Error detection not correction Move bits between devices Specifies voltage, wire speed and pin-out cables Provide logical addressing which routers use for path determination

TCP UDP SPX / HDLC EIA/TIA-232 V.35 IP IPX EXAMPLES Role of Data Flow Layers Transport Data Link Physical Reliable or unreliable delivery Error correction before retransmit Combines bits into bytes and bytes into frames Access to media using MAC address Error detection not correction Move bits between devices Specifies voltage, wire speed and pin-out cables Network Provide logical addressing which routers use for path determination

TCP UDP SPX / HDLC EIA/TIA-232 V.35 IP IPX Presentation Application Session EXAMPLES Role of Data Flow Layers Reliable or unreliable delivery Error correction before retransmit Combines bits into bytes and bytes into frames Access to media using MAC address Error detection not correction Move bits between devices Specifies voltage, wire speed and pin-out cables Transport Data Link Physical Network Provide logical addressing which routers use for path determination

Encapsulating Data Transport Data Link Physical Network Upper Layer Data TCP Header DataIP Header DataLLC Header DataMAC Header Presentation Application Session Segment Packet Bits Frame PDU FCS

Upper Layer Data De-encapsulating Data LLC Hdr + IP + TCP + Upper Layer Data MAC Header IP + TCP + Upper Layer Data LLC Header TCP+ Upper Layer Data IP Header Upper Layer Data TCP Header Transport Data Link Physical Network Presentation Application Session

© 1999, Cisco Systems, Inc پروتکل TCP/IP Interconnecting Networks with TCP/IP

Early protocol suite Universal Introduction to TCP/IP Host Internet TCP/IP Host

Computer Network Setting ipconfig Ping Tracert

TCP/IP Protocol Stack Application Presentation Session Transport Network Data Link Physical 1 Application Transport Internet Data Link Physical 1

Application Layer Overview *Used by the router Application Transport Internet Data Link Physical File Transfer - TFTP * - FTP * - NFS - SMTP Remote Login - Telnet * - rlogin * Network Management - SNMP * Name Management - DNS* File Transfer - TFTP * - FTP * - NFS - SMTP Remote Login - Telnet * - rlogin * Network Management - SNMP * Name Management - DNS*

Transport Layer Overview Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Application Transport Internet Data Link Physical Connection- Oriented Connectionless TCP Port یک عدد 16 بیتی است که معین میکند داده های Packet دریافتی مربوط به کدام Application است. مثلا اطلاعات web از port شماره 80 ارسال و یا دریافت می شود. ولی اطلاعات نرم افزار Yahoo Chat از پورت 5050 ارسال یا دریافت می شود : 2000 TCP Port:

Reliable Transport Layer Functions Synchronize Acknowledge, Synchronize Acknowledge Data Transfer (Send Segments) SenderReceiver Connection Established

Port Numbers TCP Port Numbers FTPFTP Transport Layer TELNETTELNET DNSDNS SNMPSNMP TFTPTFTP SMTPSMTP UDP Application Layer RIPRIP 224

No sequence or acknowledgment fields UDP Segment Format Source port (16) Destination port (16) Length (16) Data (if any) 1 Bit 0 Bit 15Bit 16Bit 31 Checksum (16) 8 Bytes

Internet Layer Overview OSI network layer corresponds to the TCP/IP internet layer Internet Protocol (IP) Internet Control Message Protocol (ICMP) Address Resolution Protocol (ARP) Reverse Address Resolution Protocol (RARP) Internet Protocol (IP) Internet Control Message Protocol (ICMP) Address Resolution Protocol (ARP) Reverse Address Resolution Protocol (RARP) Application Transport Internet Data Link Physical

IP Datagram Version (4) Destination IP Address (32) Options (0 or 32 if any) Data (varies if any) 1 Bit 0 Bit 15Bit 16Bit 31 Header Length (4) Priority & Type of Service (8) Total Length (16) Identification (16) Flags (3) Fragment offset (13) Time to live (8) Protocol (8)Header checksum (16) Source IP Address (32) 20 Bytes

Internet Control Message Protocol Application Transport Internet Data Link Physical Destination Unreachable Echo (Ping) Other ICMP 1 Ping Tracert

Address Resolution Protocol IP: = ??? I need the Ethernet address of جدول ARP از دو فیلد تشکیل شده است که در حافظه سیستم عامل شبکه نگهداری و بروز رسانی میشود. 1- MAC Address کامپیوتر های شبکه محلی 2- IP Address کامپیوتر های شبکه محلی یک نوع Broadcast Message

Address Resolution Protocol IP: = ??? I heard that broadcast. The message is for me. Here is my Ethernet address. I need the Ethernet address of

Address Resolution Protocol IP: Ethernet: IP: Ethernet: IP: = ??? I heard that broadcast. The message is for me. Here is my Ethernet address. I need the Ethernet address of

Address Resolution Protocol Map IP Ethernet Local ARP IP: Ethernet: IP: Ethernet: IP: = ??? I heard that broadcast. The message is for me. Here is my Ethernet address. I need the Ethernet address of

Unique addressing allows communication between end stations Path choice is based on location Location is represented by an address Introduction to TCP/IP Addresses SADAHDRDATA

IP Addressing 255 Dotted Decimal Maximum NetworkHost 32 bits

IP Addressing 255 Dotted Decimal Maximum NetworkHost Binary 32 bits

IP Addressing 255 Dotted Decimal Maximum NetworkHost Binary 32 bits Example Decimal Example Binary

Class A: Class B: Class C: Class D: Multicast Class E: Research IP Address Classes Network Host Network Host Network Host 8 bits

IP Address Classes 1 Class A: Bits: 0NNNNNNN Host Range (1-126) 1 Class B: Bits: 10NNNNNN Network Host Range ( ) 1 Class C: Bits: 110NNNNN Network Host Range ( ) 1 Class D: Bits: 1110MMMM Multicast Group Range ( )

Determining Available Host Addresses Network Host N 2 N -2 = = 65534

Network Addressing without Subnets …

Network Addressing with Subnets

Subnet Addressing E Network Interface E0 E1 New Routing Table 2160 Host E1

Subnet Addressing E0 E NetworkHost.. NetworkInterface E0 E1 New Routing Table Subnet

Subnet Mask IP Address Default Subnet Mask 8-bit Subnet Mask NetworkHost NetworkHost NetworkSubnetHost Also written as “/16” where 16 represents the number of 1s in the mask. Also written as “/24” where 24 represents the number of 1s in the mask

Decimal Equivalents of Bit Patterns = = = = = = = =

16 Network Host Subnets not in use—the default Subnet Mask without Subnets Network Number

Network number extended by eight bits Subnet Mask with Subnets 16 Network Host Subnet Network Number

Subnet Mask with Subnets (cont.) Network Host Subnet Network number extended by ten bits Network Number

Subnet Mask Exercise AddressSubnet MaskClassSubnet

Subnet Mask Exercise Answers AddressSubnet MaskClassSubnet B A A

© 1999, Cisco Systems, Inc Cisco Technology سیسکو یک تولید کننده محصولات سخت افزار شبکه است.

معرفی سیسکو دوره های آموزشی راهبردی محصولات Cisco و پیکربندی آن معرفی بعضی قابلیت ها در مدیریت شبکه نمونه ای از معماری شبکه های مرسوم

دوره های آموزشی راهبردی Cisco 1. Network support ■ CCNA Cisco Certified Network Association ■ CCNP Cisco Certified Network Professional ■ CCIE Cisco Certified Internetwork Expert 2. Network Design ■ CCDA Cisco Certified Design Association ■ CCNA Cisco Certified Network Association ■ CCDP Cisco Certified Design Professional 3. Internetwork Support ■ CCNA Cisco Certified Network Association ■ CCIP Cisco Certified Internetwork Professional ■ CCIE Cisco Certified Internetwork Expert

دوره های آموزشی راهبردی Cisco  CCNAمهارت در پیاده سازی شبکه های ساده  CCDA مهارت در طراحی شبکه های ساده  CCNP مهارت در پیاده سازی شبکه های متوسط  CCDP مهارت در طراحی شبکه های متوسط  CCIE مهارت در پیاده سازی شبکه های بزرگ و پیچیده  CCIP از طراحی زیرساخت شبکه تا پیاده سازی انواع شبکه ها

Configurations can come from many sources Configurations will act in device memory Console port Auxiliary port Interfaces PC or Unix server Web or Network Management server Virtual terminal External Configuration Sources Telnet TFTP

Router Internal Components RAM Config register ROM Flash NVRAM Interfaces حافظه ثانویه و محل قرارگرفتن سیستم عامل IOS برنامه bootstrap محل قرار گرفتن Startup Config

User Mode Limited examination of switch or router Command Prompt is hostname> There are two main EXEC modes for entering commands. First mode: Cisco IOS Software EXEC

Privileged (or enabled) Mode Detailed examination of switch or router Enables configuration and debugging Prerequisite for other configuration modes Command prompts on the device hostname# Second mode (and most commonly used): The Cisco IOS Software EXEC (cont.)

Console Logging into the Switch and Entering the Enable Password > > enable Enter password: # # disable User mode prompt Privileged mode prompt

Switch#show interfaces Switch#show version Showing Switch Initial Startup Status Switch#show running-config Display operational status of switch components

معرفی بعضی قابلیت های Cisco در مدیریت شبکه Segmentation Flexibility Security 3rd floor 2nd floor 1st floor SALESHRENG A VLAN = A broadcast domain = Logical network (subnet)

Standard versus External Access List StandardExtended Filters Based on Source. Filters Based on Source and destination. Permit or deny entire TCP/IP protocol suite. Specifies a specific IP protocol and port number. Range is 100 through 199.Range is 1 through 99

Notify Sender Outbound Access Lists If no access list statement matches then discard the packet N Y Packet Discard Bucket Choose Interface Routing Table Entry ? N Y Test Access List Statements Permit ? Y Access List ? Discard Packet N Outbound Interfaces Packet S0 E0 Inbound Interface Packets

نمونه ای از معماری یک شبکه Private Network Public Network HDSL Modem Internet

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