Chapter 1 WAN and IP Routing.pptx

JAZAN UNIVERSITY Routing & Switching Chapter -1 Fundamentals of WANs and IP Routing Adeel Ahmad Figure 1.1: A Very Basic Network This figure hows a basic local area network (LAN) that’s connected using a hub, which is basica...

JAZAN UNIVERSITY Routing & Switching Chapter -1 Fundamentals of WANs and IP Routing Adeel Ahmad Figure 1.1: A Very Basic Network This figure hows a basic local area network (LAN) that’s connected using a hub, which is basically just an antiquated device that connected wires together. Figure 1.2: A switch can break up collision domains This figure shows a network that’s been segmented with a switch, making each network segment that connects to the switch its own separate collision domain. Doing this results in a lot less yelling! Figure 1.3: Routers create an internetwork This figure depicts a router in our growing network, creating an internetwork and breaking up broadcast domains.  Figure 1.4: Internetworking devices Figure 1.4 shows how a network would look with all these internetwork devices in place. Remember, a router doesn’t just break up broadcast domains for every LAN interface, it breaks up collision domains too. Figure 1.5: Switched networks creating an internetwork Once there are only switches in our example network, things really change a lot! Figure 1.5 demonstrates a network you’ll typically stumble upon today. Switch Self-Learning How IP Addressing Helps IP Routing? How Protocols Help IP Routing  Domain Name System Domain Name Service (DNS) resolves hostnames—specifically, Internet names, such as www.lammle.com. Address Resolution Protocol ARP resolves IP addresses to Ethernet (MAC) addresses. Physical Components of Network  Physical Components of Network Let’s look closer at these devices: WLAN devices: These devices connect wireless devices such as computers, printers, and tablets to the network. Since pretty much every device manufactured today has a wireless NIC, you just need to configure a basic access point (AP) to connect to a traditional wired network. Access Points or APs: These devices allow wireless devices to connect to a wired network and extend a collision domain from a switch, and are typically in their own broadcast domain or what we’ll refer to as a Virtual LAN (VLAN). An AP can be a simple standalone device, but today they are usually managed by wireless controllers either in house or through the internet. WLAN Controllers: These are the devices that network administrators or network operations centers use to manage access points in medium to large to extremely large quantities. The WLAN controller automatically handles the configuration of wireless access points and was typically used only in larger enterprise systems. Firewalls: These devices are network security systems that monitor and control the incoming and outgoing network traffic based on predetermined security rules, and is usually an Intrusion Protection System (IPS). Cisco Adaptive Security Appliance (ASA) firewall typically establishes a barrier between a trusted, secure internal network and the Internet, which is not secure or trusted. Cisco’s new acquisition of Sourcefire put them in the top of the market with Next Generation Firewalls (NGFW) and Next Generation IPS (NGIPS), which Cisco now just calls Firepower. Cisco new Firepower runs on dedicated appliances, Cisco’s ASA’s, ISR routers and even on Meraki products.  OSI OSI was developed by the International Organization for Standardization (ISO) and introduced in 1984. It is a layered architecture (consists of seven layers). Each layer defines a set of functions which takes part in data communication.  OSI Model Layers Layer - Application Application 7 User support Layer - Layers Presentation Presentation 6 or Layer - Software Layers Session Session 5 Layer - Core layer of Transport Transport 4 the OSI Layer - Network Network 3 Network Layer - Data support Layers Data Link Link 2 or Layer - Physical Hardware Physical 1 Layers  Application Layer Application Application Application Layer is responsible for Presentation Presentation providing an interface Session Session for the users to interact Transport Transport with application services or Networking Services. Network Network Data Data Link Link Ex: Web browser, Telnet Physical etc. Physical  Examples of Networking Services Service Port No. HTTP 80 FTP 21 SMTP 25 TELNET 23 TFTP 69 Data flow from Application Layer Application Application Data Data 8 2 2 5 6 6 0 1 5 3 7 9 Presentation Presentation Session Session Transport Transport Network Network Data Data Link Link Physical Physical  Presentation Layer Presentation Layer It is Application Application responsible for defining a standard format to the data. Presentation Presentation It deals with data presentation. Session Session The major functions described at this layer are.. Transport Transport Encoding – Decoding Eg: ASCII, EBCDIC (Text) Network Network JPEG,GIF,TIFF (Graphics) MIDI,WAV (Voice) Data Data Link Link MPEG,DAT,AVI (Video) Encryption – Decryption Physical Physical Compression – Decompression Data flow from Presentation Layer Application Application Data Data Presentation Presentation Data Data Session Session Transport Transport Network Network Data Data Link Link Physical Physical  Session Layer Application Session Layer Application It is responsible for Presentation Presentation establishing, maintaining and terminating the sessions. Session Session Session ID is used to identify a Transport Transport session or interaction. Examples : Network Network RPC Remote Procedural Call SQL Structured Query Language Data Data Link Link ASP AppleTalk Session protocol Physical Physical Data flow from Session Layer Application Application Data Data Presentation Presentation Data Data Session Session Data Data Transport Transport Network Network Data Data Link Link Physical Physical  Transport Layer Transport Layer Application Application It provides data delivery Presentation Presentation mechanism between the applications in the network. Session Session The major functions described at the Transport Layer are.. Transport Transport Identifying Service Network Network Multiplexing & De-multiplexing Segmentation Data Data Link Link Sequencing & Reassembling Error Correction Physical Physical Flow Control  Identifying a Service Identification of Services is done using port Numbers. Port is a logical communication Channel Total No. Ports 0 – 65535 Reserved Ports 1 - 1023 Open Ports 1024 – 65535 Multiplexing & De- multiplexing Application Application Presentation Presentation Session Session 8 2 2 5 6 6 0 1 5 3 7 9 Transport Transport TCP - UDP - 6 17 Network Network Data Data Link Link Physical Physical  Transport Layer Protocols The protocols which takes care of Data Transportation at Transport layer are…TCP, UDP TCP UDP Transmission Control User Datagram Protocol Protocol Connection Oriented Connection Less Supports Ack’s No support for Ack’s Reliable Unreliable communication communication Slower data Faster data Transportation Transportation Protocol No is 6 Protocol No is 17 Eg: HTTP, FTP, SMTP Eg: DNS, DHCP, TFTP  Segmentation HELLO! HOWHELLO! HOW ARE YOU ? ARE YOU? Data Data  Sequencing HELLO! HOWHELLO! HOW ARE YOU ? ARE YOU? Data Data  Sequencing HOW ? ARE HELLO! YOU  Sequencing HELLO! HOW ARE YOU ? 1/5 2/5 3/5 4/5 5/5 Data Data  Sequencing HOW ? ARE HELLO! YOU 2/5 5/5 3/5 1/5 4/5 Data flow from Transport Layer Application Application Data Data Presentation Presentation Data Data Session Session Data Data Transport Transport Segment TH Data Segment TH Data Network Network Data Data Link Link Physical Physical  Network Layer Network Layer Application Application It provides logical addressing & Presentation Presentation Path determination (Routing) The protocols that work in this Session Session layer are: Routed Protocols: Transport Transport IP, IPX, AppleTalk.. Etc Routed protocols used to carry user Network Network data between hosts. Data Routing Protocols: Data Link Link RIP, OSPF.. Etc Physical Physical Routing protocols performs Path determination (Routing). Data flow from Network Layer Application Application Data Data Presentation Presentation Data Data Device that works at Network Layer Session Session Data Data is Router Transport Transport Segment TH Data Segment TH Data Segme Segme Network Network NHPacket NHPacket nt nt Data Data Link Link Physical Physical  Data link Layer Application Application Data link Layer Presentation Presentation It has 2 sub layers MAC (Media Access Control) It Session Session provides reliable transit of data Transport Transport across a physical link. It also provides ERROR DETECTION using CRC (Cyclic Network Network Redundancy Check) Data Data Link Link Ex: Ethernet, Token ring…etc LLC (Logical Link Control) Physical Physical It provides communication with Network layer. Data flow from Data link Layer Application Application Data Data Presentation Presentation Data Data Session Session Data Data Devices that work Transport Transport Segment TH Data Segment TH Data at Data link layer are Switch, Bridge Segme Segme Network Network NHPacket NHPacket etc.. nt nt D Pack Pack D D Frame D Data Data Link Link Frame T T et et H H Physical Physical  Physical Layer Application Application Physical Layer It defines the electrical, Mechanical & Presentation Presentation functional specifications for Session Session communication between the Network Transport devices. Transport The functions described at this layer are.. Network Network Encoding/decoding: It is the process of converting the binary data Data Data Link Link into signals based on the type of the media. Copper media : Electrical signals of different voltages Physical Physical Fiber media: Light pulses of different wavelengths Wireless media: Radio frequency waves  Data flow from Physical Layer Application Application Data Data Presentation Presentation Data Data Session Session Data Data Transport Transport Segment TH Data Segment TH Data Segme Segme Devices that work at Network Network NHPacket NHPacketnt nt physical layer are.. Hub, Repeater.. Etc D Pack Pack D D Frame D Data Data Link Link Frame T T et et H H Physical Physical Bits Bits Comparison between OSI & TCP/IP Model Application Application Presentation Presentation Application Application Session Session Transport Transport Host Host to to Host Host Network Network Internet Internet Data Data Link Link Network Network Access Access Physical Physical