Tài liệu CNNA3-Chapter 3 pdf

CCNA3-1 Chapter 3-1 Chapter 3 Chapter 3 Virtual Local Area Networks Virtual Local Area Networks (VLANs) (VLANs) Part I Part I CCNA3-2 Chapter 3-1 Virtual Local Area Networks Virtual Local Area Networks Introducing VLANs Introducing VLANs CCNA3-3 Chapter 3-1 Defining VLANs Defining VLANs • In In traditional traditional switched LANs, switched LANs, the physical topology is the physical topology is closely related to the logical closely related to the logical topology. topology. • Generally, workstations must Generally, workstations must be be grouped by their physical grouped by their physical proximity to a switch proximity to a switch . . • To communicate among To communicate among LANs, each segment must LANs, each segment must have a have a separate port separate port on the on the backbone device or a backbone device or a connection to a common connection to a common backbone. backbone. Separate Broadcast Separate Broadcast Domains Domains Separate Broadcast Separate Broadcast Domains Domains CCNA3-4 Chapter 3-1 Defining VLANs Defining VLANs • VLANs provide segmentation VLANs provide segmentation based on based on broadcast domains broadcast domains . . • VLANs logically segment VLANs logically segment switched networks based on switched networks based on the the functions, project teams, functions, project teams, or applications or applications of the of the organization organization regardless of the regardless of the physical location physical location or or connections to the network. connections to the network. • Communication among Communication among VLANs still require a router. VLANs still require a router. BUT, BUT, only one physical only one physical connection connection will handle all will handle all routing. routing. Separate Broadcast Separate Broadcast Domains Domains Separate Broadcast Separate Broadcast Domains Domains CCNA3-5 Chapter 3-1 Defining VLANs Defining VLANs • VLANs are created to provide segmentation services VLANs are created to provide segmentation services traditionally provided by physical routers in LAN traditionally provided by physical routers in LAN configurations. configurations. • They address: They address: • Scalability Scalability • Security Security • Network Management Network Management • Broadcast Filtering Broadcast Filtering • Traffic Flow Management Traffic Flow Management • Switches Switches may not forward may not forward any traffic between VLANs, as this any traffic between VLANs, as this would violate the integrity of the VLAN broadcast domain. would violate the integrity of the VLAN broadcast domain. • Traffic Traffic must be routed must be routed between VLANs. between VLANs. CCNA3-6 Chapter 3-1 What Does This Mean? What Does This Mean? Requirements: Requirements: - Different department on - Different department on each floor. each floor. - Three different LANs per floor. - Three different LANs per floor. - Separate networks - Separate networks Requirements: Requirements: - Different department on - Different department on each floor. each floor. - Three different LANs per floor. - Three different LANs per floor. - Separate networks - Separate networks With routers: With routers: Expen Expen $ $ ive! ive! - 4 Ports each 4 Ports each - 3 hubs / floor 3 hubs / floor - 10 Broadcast domains 10 Broadcast domains - Inefficient traffic flow - Inefficient traffic flow With routers: With routers: Expen Expen $ $ ive! ive! - 4 Ports each 4 Ports each - 3 hubs / floor 3 hubs / floor - 10 Broadcast domains 10 Broadcast domains - Inefficient traffic flow - Inefficient traffic flow CCNA3-7 Chapter 3-1 What Does This Mean? What Does This Mean? With switches: With switches: - More scalable More scalable - Easier to manage Easier to manage - 1 Router 1 Router - 3 Broadcast Domains 3 Broadcast Domains - Efficient traffic flow - Efficient traffic flow With switches: With switches: - More scalable More scalable - Easier to manage Easier to manage - 1 Router 1 Router - 3 Broadcast Domains 3 Broadcast Domains - Efficient traffic flow - Efficient traffic flow CCNA3-8 Chapter 3-1 Defining VLANs Defining VLANs • A VLAN, then, is a broadcast domain (IP Subnet) created by A VLAN, then, is a broadcast domain (IP Subnet) created by one or more switches. one or more switches. CCNA3-9 Chapter 3-1 Defining VLANs Defining VLANs • The above design shows 3 separate broadcast domains The above design shows 3 separate broadcast domains created using one router with 3 ports and 3 switches. created using one router with 3 ports and 3 switches. • The router filters the broadcasts for each LAN. The router filters the broadcasts for each LAN. CCNA3-10 Chapter 3-1 Defining VLANs Defining VLANs • A better design still creates the 3 separate broadcast A better design still creates the 3 separate broadcast domains but only requires 1 switch. domains but only requires 1 switch. • The router provides broadcast filtering over a The router provides broadcast filtering over a single link single link . . One Physical One Physical Link Link One Physical One Physical Link Link [...]... works between a switch, a Cisco IP phone, and a computer CCNA3- 23 Chapter 3- 1 Types of Port-Based VLANs • Voice VLANs: VLAN 150 is designed VLAN 150 is designed to carry voice traffic to carry voice traffic Connections Connections CCNA3-24 Chapter 3- 1 Types of Port-Based VLANs • Voice VLANs: A Cisco IP Phone is a switch Port 3 connects to a Port 3 connects to a PC or other device PC or other device Port... • Voice VLANs: Should make more sense now… Should make more sense now… CCNA3-28 Chapter 3- 1 Network Traffic Types Management Traffic Management Traffic CDP CDP SNMP SNMP Rmon Rmon CCNA3-29 Chapter 3- 1 Network Traffic Types IP Telephony Traffic IP Telephony Traffic Signaling Signaling Data Packets Data Packets CCNA3 -30 Chapter 3- 1 Network Traffic Types IP Multicast Traffic IP Multicast Traffic VLAN Configuration... Applications Shared Applications CCNA3 -32 Chapter 3- 1 Network Traffic Types Scavenger Class Traffic Scavenger Class Traffic Less than best-effort services Less than best-effort services Typically entertainment oriented Typically entertainment oriented Peer-to-Peer Media Sharing Peer-to-Peer Media Sharing (KaZaa, Napster), (KaZaa, Napster), Gaming Gaming CCNA3 -33 Chapter 3- 1 Switch Port Membership Modes... configure a port specifying: • The type of traffic • The VLANs to which it belongs CCNA3 -34 Chapter 3- 1 Switch Port Membership Modes • Static VLAN: • Ports on a switch are manually assigned to a VLAN • Static VLANs are configured using the Cisco CLI or a GUI Management application (e.g Cisco Network Assistant) CCNA3 -35 Chapter 3- 1 Switch Port Membership Modes • Dynamic VLAN: • Configured using a special server... device switch or VoIP device CCNA3-25 Chapter 3- 1 Types of Port-Based VLANs • Voice VLANs: A Cisco IP Phone is a switch Switch S3 is configured Switch S3 is configured to carry voice traffic on to carry voice traffic on VLAN 150 and data VLAN 150 and data traffic on VLAN 20 traffic on VLAN 20 MORE on the tagging process later… MORE on the tagging process later… CCNA3-26 Receiving: Receiving: Phone... example, an e-learning development platform for faculty CCNA3- 13 Chapter 3- 1 VLAN ID Ranges • When configured, the number that is assigned to the VLAN becomes the VLAN ID • The numbers to be assigned are divided into two different ranges: • Normal Range: 1 – 1005 • Extended Range: 1006 - 4096 • Each range has its own characteristics CCNA3-14 Chapter 3- 1 VLAN ID Ranges • Normal Range: 1 – 1005 • Used in small-... device contacts it • Today, there is essentially one method of implementing VLANs: Port-Based CCNA3-17 Chapter 3- 1 Types of Port-Based VLANs • Defined by the type of traffic they support or by the functions they perform • Data VLAN • Default VLAN • Native VLAN • Management VLAN • Voice VLAN CCNA3-18 Chapter 3- 1 Types of Port-Based VLANs • Data VLAN: • Configured to carry only user-generated traffic •... CCNA3-11 Chapter 3- 1 Benefits of VLANs • Security: • Groups with specific security needs are isolated from the rest of the network • Cost Reduction: • Need for expensive hardware upgrades is reduced • Better use of existing bandwidth and links • Higher Performance: • Dividing large, flat Layer 2 networks into separate broadcast domains reduces unnecessary traffic on each new subnet CCNA3-12 Chapter 3- 1... for the PC Chapter 3- 1 Types of Port-Based VLANs • Voice VLANs: A Cisco IP Phone is a switch Link to the switch acts as a Link to the switch acts as a trunk link to carry both trunk link to carry both voice and data traffic voice and data traffic CDP is used to CDP is used to communicate communicate between the switch between the switch and the phone and the phone CDP CCNA3-27 Chapter 3- 1 Types of Port-Based... Router Configuration Router Configuration CCNA3 -31 IP/TV Broadcasts IP/TV Broadcasts Sent from a particular source address to a Sent from a particular source address to a multicast group that is identified by a single multicast group that is identified by a single IP and MAC destination-group address pair IP and MAC destination-group address pair Chapter 3- 1 Network Traffic Types Normal Data Traffic . CCNA3-1 Chapter 3- 1 Chapter 3 Chapter 3 Virtual Local Area Networks Virtual Local Area Networks (VLANs) (VLANs) Part I Part I CCNA3-2 Chapter 3- 1 Virtual. 3 hubs / floor 3 hubs / floor - 10 Broadcast domains 10 Broadcast domains - Inefficient traffic flow - Inefficient traffic flow CCNA3-7 Chapter 3- 1 What