CẤU TRÚC MẠNG LAN (PHÂN 3) ppt

CCNA – Semester 3 Chapter 3: VLANs CCNA Exploration 4.0 2 Objectives • Explain the role of VLANs in a network • Explain the role of trunking VLANs in a network • Configure VLANs on the switches in a network topology • Troubleshoot the common software or hardware configuration problems associated with VLANs on switches in a network topology 3 Introducing VLANs 4 Introducing VLANs 5 What is a VLAN? 6 What is a VLAN? 7 Benefits of a VLAN 8 Introducing VLANs 9 Types of VLANs • Today there is essentially one way of implementing VLANs - port-based VLANs. A port-based VLAN is associated with a port called an access VLAN. • However in the network there are a number of terms for VLANs. Some terms define the type of network traffic they carry and others define a specific function a VLAN performs. VLAN Types: • Data VLAN: – Is a VLAN that is configured to carry only user-generated traffic – A VLAN could carry voice-based traffic or traffic used to manage the switch, but this traffic would not be part of a data VLAN. – Sometimes referred to as a user VLAN 10 Types of VLANs • Default VLAN: – All switch ports become a member of the default VLAN after the initial boot up of the switch. – The default VLAN for Cisco switches is VLAN 1, you cannot rename it and you can not delete it. – Layer 2 control traffic, such as CDP and spanning tree protocol (STP) traffic, will always be associated with VLAN 1 - this cannot be changed. – It is a security best practice to change the default VLAN to a VLAN other than VLAN 1 • Note: Some network administrators use the term "default VLAN" to mean a VLAN other than VLAN 1 defined by the network administrator as the VLAN that all ports are assigned to when they are not in use. In this case, the only role that VLAN 1 plays is that of handling Layer 2 control traffic for the network. [...]... common to legacy LAN scenarios – It is a best practice to use a VLAN other than VLAN 1 as the native VLAN 11 Types of VLANs • Management VLAN – A management VLAN is any VLAN you configure to access the management capabilities of a switch – VLAN 1 would serve as the management VLAN if you did not proactively define a unique VLAN to serve as the management VLAN – You assign the management VLAN an IP address... of multiple VLANs over a single link A VLAN trunk allows you to extend the VLANs across an entire network Cisco supports IEEE 802.1Q for coordinating trunks on Fast Ethernet and Gigabit Ethernet interfaces A VLAN trunk does not belong to a specific VLAN, rather it is a conduit for VLANs between switches and routers 30 VLAN Trunks • Without VLAN Trunks 31 VLAN Trunks • With VLAN Trunks 32 VLAN Trunks... configured for a specific VLAN You need to configure an SVI for a VLAN if you want to route between VLANs or to provide IP host connectivity to the switch By default, an SVI is created for the default VLAN (VLAN 1) to permit remote switch administration 27 Controlling Broadcast Domains with VLANs 28 VLAN Trunking 29 VLAN Trunks • • • • • It is hard to describe VLANs without mentioning VLAN trunks A trunk is...Types of VLANs • Native VLAN: – A native VLAN is assigned to an 802.1Q trunk port An 802.1Q trunk port supports traffic coming from many VLANs (tagged traffic) as well as traffic that does not come from a VLAN (untagged traffic) The 802.1Q trunk port places untagged traffic on the native VLAN – Native VLANs are set out in the IEEE 802.1Q specification to maintain... connected to the port • Voice VLAN - A port is configured to be in voice mode so that it can support an IP phone attached to it Before you configure a voice VLAN on the port, you need to first configure a VLAN for voice and a VLAN for data 20 Switch Port Membership Modes 21 Switch Port Membership Modes • Voice Mode configuration 22 Controlling Broadcast Domains with VLANs • Without VLANs: In normal operation,... with VLANs • With VLANs: the broadcast frame arrives at the only other computer in the network configured on the same VLAN 24 Controlling Broadcast Domains with Switches and Routers Intra-VLAN Communication • PC1 want to communicate with PC4 25 Controlling Broadcast Domains with Switches and Routers Inter-VLAN Communication • PC1 want to communicate with PC5 26 Controlling Broadcast Domains with VLANs... address and subnet mask A switch can be managed via HTTP, Telnet, SSH, or SNMP Since the out-of-the-box configuration of a Cisco switch has VLAN 1 as the default VLAN, you see that VLAN 1 would be a bad choice as the management VLAN 12 Types of VLANs • Voice VLANs VoIP traffic requires: – Assured bandwidth to ensure voice quality – Transmission priority over other types of network traffic – Ability... can be configured to support these VLAN types: • Static VLAN - Ports on a switch are manually assigned to a VLAN • Dynamic VLAN - This mode is not widely used in production networks and is not explored in this course However, it is useful to know what a dynamic VLAN is A dynamic port VLAN membership is configured using a special server called a VLAN Membership Policy Server (VMPS), based on the source... which VLAN the frame should belong to • When Ethernet frames are placed on a trunk they need additional information about the VLANs they belong to This is accomplished by using the 802.1q encapsulation header This header adds a tag to the original Ethernet frame specifying the VLAN for which the frame belongs to 33 VLAN Trunks • VLAN Frame Tagging EtherType : Tag Protocol ID (TPID) 34 Native VLANs and... Types of VLANs • Voice VLAN 14 Types of VLANs • Cisco IP Phone 15 Network Traffic Types • Network Management and Control Traffic 16 Network Traffic Types • IP Telephony 17 Network Traffic Types • IP Multicast 18 Network Traffic Types • Normal Data 19 Switch Port Membership Modes • Switch ports are Layer 2-only interfaces associated with a physical port A port can be configured to support these VLAN types: . with VLANs on switches in a network topology 3 Introducing VLANs 4 Introducing VLANs 5 What is a VLAN? 6 What is a VLAN? 7 Benefits of a VLAN 8 Introducing VLANs 9 Types of VLANs. common to legacy LAN scenarios. – It is a best practice to use a VLAN other than VLAN 1 as the native VLAN. 12 Types of VLANs • Management VLAN – A management VLAN is any VLAN you configure. configuration of a Cisco switch has VLAN 1 as the default VLAN, you see that VLAN 1 would be a bad choice as the management VLAN. 13 Types of VLANs • Voice VLANs VoIP traffic requires: – Assured