Chapter 3: VLANs doc

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. [...]... Switch Port Membership Modes • Voice Mode configuration 22 Controlling Broadcast Domains with VLANs • Without VLANs: In normal operation, when a switch receives a broadcast frame on one of its ports, it forwards the frame out all other ports on the switch 23 Controlling Broadcast Domains with VLANs • With VLANs: the broadcast frame arrives at the only other computer in the network configured on the...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... Domains with VLANs and Layer 3 Forwarding SVI: switch virtual interface • SVI is a logical interface 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 a point-to-point link between one or more Ethernet switch interfaces and another networking device, such as a router or a switch Ethernet trunks carry the traffic 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... 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 802.1Q Trunking 35 Native VLANs and 802.1Q Trunking 36 ... 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 to be routed around congested areas on the network... switch or other voice-over-IP (VoIP) device – Port 2 is an internal 10/100 interface that carries the IP phone traffic – Port 3 (access port) connects to a PC or other device 13 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... 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 802.1Q Frame Tagging • Switches are layer 2 devices, use the Ethernet frame header... IEEE 802.1Q specification to maintain backward compatibility with untagged traffic 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 . 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. 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. 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