virtual lan (vlan) w.lilakiatsakun. vlan overview (1) a vlan allows a network administrator to...

Virtual LAN (VLAN)Virtual LAN (VLAN)

W.lilakiatsakunW.lilakiatsakun

VLAN Overview (1)VLAN Overview (1)

• A VLAN allows a network administrator to A VLAN allows a network administrator to create create groups of logically networked devices that act as if groups of logically networked devices that act as if they are on their own independent networkthey are on their own independent network, even if , even if they share a common infrastructure with other they share a common infrastructure with other VLANs. VLANs.

• Using VLANs, you can Using VLANs, you can logically segment switched logically segment switched networksnetworks based on functions, departments, or based on functions, departments, or project teams. project teams.

• You can also use a VLAN to You can also use a VLAN to geographically geographically structure your networkstructure your network to support the growing to support the growing reliance of companies on home-based workers. reliance of companies on home-based workers.

• These VLANs allow the network administrator to These VLANs allow the network administrator to implement implement access and security policiesaccess and security policies to to particular groups of users.particular groups of users.

VLAN Overview (2)VLAN Overview (2)

VLAN in detailsVLAN in details (1)(1)

• A VLAN is a A VLAN is a logically separate IP subnetworklogically separate IP subnetwork..

• VLANs allow multiple IP networks and subnets VLANs allow multiple IP networks and subnets to exist on the same switched network. to exist on the same switched network.

• For computers to communicate on the same For computers to communicate on the same VLAN, each VLAN, each must have an IP address and a must have an IP address and a subnet mask that is consistent for that VLANsubnet mask that is consistent for that VLAN. .

• The switch has to be configured with the VLAN The switch has to be configured with the VLAN and each port in the VLAN must be assigned to and each port in the VLAN must be assigned to the VLAN. the VLAN.


• A switch port with a singular VLAN A switch port with a singular VLAN configured on it is called an configured on it is called an access portaccess port. .

• Remember, just because two computers Remember, just because two computers are physically connected to the same are physically connected to the same switch does not mean that they can switch does not mean that they can communicate.communicate.

• Devices Devices on two separate networks and on two separate networks and subnets must communicate via a routersubnets must communicate via a router (Layer 3), whether or not VLANs are used. (Layer 3), whether or not VLANs are used.

Benefits of VLAN (1)Benefits of VLAN (1)

• SecuritySecurity - Groups that have sensitive data - Groups that have sensitive data are separated from the rest of the network, are separated from the rest of the network, decreasing the chances of confidential decreasing the chances of confidential information breaches. information breaches. – Faculty computers are on VLAN 10 and Faculty computers are on VLAN 10 and

completely separated from student and guest completely separated from student and guest data traffic.data traffic.

• Cost reductionCost reduction - Cost savings result from - Cost savings result from less need for expensive network upgrades less need for expensive network upgrades and more efficient use of existing and more efficient use of existing bandwidth and uplinks.bandwidth and uplinks.


• Higher performanceHigher performance - Dividing flat Layer 2 - Dividing flat Layer 2 networks into multiple logical workgroups networks into multiple logical workgroups (broadcast domains) (broadcast domains) reduces unnecessary reduces unnecessary traffic on the network and boosts performancetraffic on the network and boosts performance. .

• Broadcast storm mitigationBroadcast storm mitigation - Dividing a network - Dividing a network into VLANs reduces the number of devices that into VLANs reduces the number of devices that may participate in a broadcast storm. may participate in a broadcast storm. – In the figure you can see that although there are six In the figure you can see that although there are six

computers on this network, there are only three computers on this network, there are only three broadcast domains: Faculty, Student, and Guest. broadcast domains: Faculty, Student, and Guest.


• Improved IT staff efficiencyImproved IT staff efficiency - VLANs make it - VLANs make it easier to manage the network because users easier to manage the network because users with similar network requirements share the with similar network requirements share the same VLAN. same VLAN. – When you provision a new switch, all the policies When you provision a new switch, all the policies

and procedures already configured for the and procedures already configured for the particular VLAN are implemented when the ports particular VLAN are implemented when the ports are assigned. are assigned.

– It is also easy for the IT staff to identify the function It is also easy for the IT staff to identify the function of a VLAN by giving it an appropriate name. of a VLAN by giving it an appropriate name.

– In the figure, for easy identification VLAN 20 could In the figure, for easy identification VLAN 20 could be named "Student", VLAN 10 could be named be named "Student", VLAN 10 could be named "Faculty", and VLAN 30 "Guest." "Faculty", and VLAN 30 "Guest."


• Simpler project or application Simpler project or application managementmanagement - VLANs aggregate users - VLANs aggregate users and network devices to support and network devices to support business or geographic requirements. business or geographic requirements. – Having separate functions makes managing Having separate functions makes managing

a project or working with a specialized a project or working with a specialized application easier, for example, an e-application easier, for example, an e-learning development platform for faculty. learning development platform for faculty.

– It is also easier to determine the scope of It is also easier to determine the scope of the effects of upgrading network services.the effects of upgrading network services.


• Simpler project or application Simpler project or application managementmanagement - VLANs aggregate users - VLANs aggregate users and network devices to support and network devices to support business or geographic requirements. business or geographic requirements. – Having separate functions makes Having separate functions makes

managing a project or working with a managing a project or working with a specialized application easier, for specialized application easier, for example, an e-learning development example, an e-learning development platform for faculty. platform for faculty.

– It is also easier to determine the scope of It is also easier to determine the scope of the effects of upgrading network services.the effects of upgrading network services.

Introducing VLANsIntroducing VLANs (1)(1)• VLAN ID Ranges - VLAN ID Ranges - Access VLANs are divided into either Access VLANs are divided into either

a normal range or an extended range.a normal range or an extended range.• Normal Range VLANs -Normal Range VLANs -Used in small- and medium-sized Used in small- and medium-sized

business and enterprise networks.business and enterprise networks.• Identified by a VLAN ID between 1 and 1005. Identified by a VLAN ID between 1 and 1005.

– IDs 1002 through 1005 are reserved for Token Ring and FDDI IDs 1002 through 1005 are reserved for Token Ring and FDDI VLANs.VLANs.

– IDs 1 and 1002 to 1005 are automatically created and cannot IDs 1 and 1002 to 1005 are automatically created and cannot be removed. be removed.

– Configurations are stored within a VLAN database file, called Configurations are stored within a VLAN database file, called vlan.datvlan.dat. .

– The vlan.dat file is located in the flash memory of the switch. The vlan.dat file is located in the flash memory of the switch.

• The VLAN trunking protocol (VTP), which helps manage The VLAN trunking protocol (VTP), which helps manage VLAN configurations between switches, can only learn VLAN configurations between switches, can only learn normal range VLANs and stores them in the VLAN normal range VLANs and stores them in the VLAN database file.database file.

Introducing VLANsIntroducing VLANs (2)(2)

• Extended Range VLANs - Extended Range VLANs - Enable service Enable service providers to extend their infrastructure to a providers to extend their infrastructure to a greater number of customers. greater number of customers. – Some global enterprises could be large enough Some global enterprises could be large enough

to need extended range VLAN IDs.to need extended range VLAN IDs.

• Are identified by a VLAN ID between Are identified by a VLAN ID between 1006 1006 and 4094.and 4094.

• Support fewer VLAN features than normal Support fewer VLAN features than normal range VLANs.range VLANs.

• Are saved in the Are saved in the running configuration filerunning configuration file. . • VTP VTP does not learndoes not learn extended range VLANs. extended range VLANs.


• 255 VLANs Configurable255 VLANs Configurable– One Cisco Catalyst 2960 switch can One Cisco Catalyst 2960 switch can

support up to 255 normal range and support up to 255 normal range and extended range VLANs, although the extended range VLANs, although the number configured affects the number configured affects the performance of the switch hardware. performance of the switch hardware.

Types of VLANs - Types of VLANs - Data VLANData VLAN (1)(1)

• Data VLANData VLAN - - a VLAN that is configured a VLAN that is configured to carry only user-generated traffic. to carry only user-generated traffic.

• It is common practice to separate It is common practice to separate voice and management trafficvoice and management traffic from from data traffic. data traffic.

• A data VLAN is sometimes referred to A data VLAN is sometimes referred to as a as a user VLANuser VLAN..

Types of VLANsTypes of VLANs - - Data VLANData VLAN (2)(2)

Data VLAN

Types of VLANs- Types of VLANs- Default VLANDefault VLAN (1)(1)

• All switch ports become All switch ports become a member of the a member of the default VLAN after the initial boot up of the default VLAN after the initial boot up of the switchswitch. . – Having all the switch ports participate in the default Having all the switch ports participate in the default

VLAN makes them all part of the same broadcast VLAN makes them all part of the same broadcast domain. domain.

– This allows any device connected to any switch port This allows any device connected to any switch port to communicate with other devices on other switch to communicate with other devices on other switch ports.ports.

– The default VLAN for Cisco switches is VLAN 1. The default VLAN for Cisco switches is VLAN 1. – VLAN 1 has all the features of any VLAN, except that VLAN 1 has all the features of any VLAN, except that

you cannot rename it and you can not delete it. you cannot rename it and you can not delete it.

Types of VLANsTypes of VLANs- - Default VLANDefault VLAN (2)(2)

– Layer 2 control traffic, such as CDP and Layer 2 control traffic, such as CDP and spanning tree protocol trafficspanning tree protocol traffic, will always be , will always be associated with VLAN 1 - this cannot be associated with VLAN 1 - this cannot be changed. changed.

– In the figure, VLAN 1 traffic is forwarded over In the figure, VLAN 1 traffic is forwarded over the VLAN trunks connecting the S1, S2, and S3 the VLAN trunks connecting the S1, S2, and S3 switches. switches.

– It is a security best practice to change the It is a security best practice to change the default VLAN to a VLAN other than VLAN 1default VLAN to a VLAN other than VLAN 1; this ; this entails configuring all the ports on the switch to entails configuring all the ports on the switch to be associated with a default VLAN other than be associated with a default VLAN other than VLAN 1. VLAN 1.

Types of VLANsTypes of VLANs- - Default VLANDefault VLAN (3)(3)

Default VLAN

Types of VLANsTypes of VLANs - - Native VLANNative VLAN (1)(1)

• A native VLAN is assigned to an 802.1Q trunk A native VLAN is assigned to an 802.1Q trunk portport. .

• An 802.1Q trunk port supports traffic coming An 802.1Q trunk port supports traffic coming from many VLANs (tagged traffic) as well as from many VLANs (tagged traffic) as well as traffic that does not come from a VLAN traffic that does not come from a VLAN (untagged traffic). (untagged traffic).

• The 802.1Q trunk port places untagged traffic The 802.1Q trunk port places untagged traffic on the native VLAN. on the native VLAN.

• In the figure, the native VLAN is VLAN 99.In the figure, the native VLAN is VLAN 99.• Untagged traffic is generated by a computer Untagged traffic is generated by a computer

attached to a switch port that is configured attached to a switch port that is configured with the native VLAN. with the native VLAN.


• Native VLANs are set out in the IEEE Native VLANs are set out in the IEEE 802.1Q802.1Q specification to maintain backward specification to maintain backward compatibility with untagged traffic compatibility with untagged traffic common to legacy LAN scenarios. common to legacy LAN scenarios.

• For our purposes, a native VLAN serves as For our purposes, a native VLAN serves as a common identifier on opposing ends of a a common identifier on opposing ends of a trunk link. trunk link.

• It is a best practice to use a VLAN other It is a best practice to use a VLAN other than VLAN 1 as the native VLAN.than VLAN 1 as the native VLAN.

Types of VLANsTypes of VLANs - - Management Management VLANVLAN (1)(1)• A management VLAN is any VLAN you configure A management VLAN is any VLAN you configure

to access the management capabilities of a to access the management capabilities of a switchswitch..

• VLAN 1 would serve as the management VLAN if VLAN 1 would serve as the management VLAN if you did not proactively define a unique VLAN to you did not proactively define a unique VLAN to serve as the management VLAN. serve as the management VLAN.

• You assign the management VLAN an IP address You assign the management VLAN an IP address and subnet mask. and subnet mask. – A switch can be managed via HTTP, Telnet, SSH, or A switch can be managed via HTTP, Telnet, SSH, or

SNMP. SNMP. • VLAN 1 is normally used as the default VLAN, VLAN 1 is normally used as the default VLAN,

– VLAN1 would be a bad choice as the management VLAN1 would be a bad choice as the management VLAN; you wouldn't want an arbitrary user connecting VLAN; you wouldn't want an arbitrary user connecting to a switch to default to the management VLAN. to a switch to default to the management VLAN.

Types of VLANsTypes of VLANs - - Management Management VLANVLAN (2)(2)

Types of VLANsTypes of VLANs - - Voice VLAN Voice VLAN (1)(1)

• It is easy to appreciate why a separate It is easy to appreciate why a separate VLAN is needed VLAN is needed to support Voice over IPto support Voice over IP (VoIP).(VoIP).

• VoIP traffic requires:VoIP traffic requires:– Assured bandwidth to ensure voice quality Assured bandwidth to ensure voice quality – Transmission priority over other types of Transmission priority over other types of

network trafficnetwork traffic– Ability to be routed around congested areas on Ability to be routed around congested areas on

the networkthe network– Delay of less than 150 milliseconds (ms) across Delay of less than 150 milliseconds (ms) across

the networkthe network

Types of VLANsTypes of VLANs - - Voice VLAN Voice VLAN (3)(3)• A Cisco Phone is a SwitchA Cisco Phone is a Switch

• The Cisco IP Phone contains an integrated three-port The Cisco IP Phone contains an integrated three-port 10/100 switch as shown in the Figure. The ports 10/100 switch as shown in the Figure. The ports provide dedicated connections to these devices:provide dedicated connections to these devices:

• Port 1 connects to the switch or other voice-over-IP Port 1 connects to the switch or other voice-over-IP (VoIP) device.(VoIP) device.

• Port 2 is an internal 10/100 interface that carries the Port 2 is an internal 10/100 interface that carries the IP phone traffic.IP phone traffic.

• Port 3 (access port) connects to a PC or other device.Port 3 (access port) connects to a PC or other device.

Types of VLANsTypes of VLANs - - Network Network traffic type (1)traffic type (1)

• Network Management and Control Traffic Network Management and Control Traffic

• Many different types of network Many different types of network management and control traffic can be management and control traffic can be present on the network, such as Cisco present on the network, such as Cisco Discovery Protocol (CDP) updates, Simple Discovery Protocol (CDP) updates, Simple Network Management Protocol (SNMP) Network Management Protocol (SNMP) traffic, and Remote Monitoring (RMON) traffic, and Remote Monitoring (RMON) traffic.traffic.

Types of VLANsTypes of VLANs - - Network Network traffic type (3)traffic type (3)• IP TelephonyIP Telephony

• The types of IP telephony traffic are The types of IP telephony traffic are signaling traffic and voice traffic. signaling traffic and voice traffic.

• Signaling traffic is, responsible for call Signaling traffic is, responsible for call setup, progress, and teardown, and setup, progress, and teardown, and traverses the network end to end. traverses the network end to end.

• The other type of telephony traffic consists The other type of telephony traffic consists of data packets of the actual voice of data packets of the actual voice conversation. conversation.

• Data traffic should be associated with a Data traffic should be associated with a data VLAN (other than VLAN 1), and voice data VLAN (other than VLAN 1), and voice traffic is associated with a voice VLAN.traffic is associated with a voice VLAN.

Types of VLANsTypes of VLANs - - Network Network traffic type (5)traffic type (5)• IP MulticastIP Multicast

• IP multicast traffic is sent from IP multicast traffic is sent from a particular source a particular source address to a multicast groupaddress to a multicast group that is identified by a that is identified by a single IP and MAC destination-group address pair. single IP and MAC destination-group address pair.

• Multicast traffic can produce Multicast traffic can produce a large amount of dataa large amount of data streaming across the network. streaming across the network.

• When the network must support multicast traffic, When the network must support multicast traffic, VLANs should be configured to ensure multicast traffic VLANs should be configured to ensure multicast traffic only goes to those user devicesonly goes to those user devices that use the service that use the service provided, such as remote video or audio applications. provided, such as remote video or audio applications.

• Routers must be configured to ensure that multicast Routers must be configured to ensure that multicast traffic is forwarded to the network areas where it is traffic is forwarded to the network areas where it is requested.requested.

Types of VLANsTypes of VLANs - - Network Network traffic type (7)traffic type (7)• Normal DataNormal Data

• Normal data traffic is related to file Normal data traffic is related to file creation and storage, print services, e-mail creation and storage, print services, e-mail database access, and other shared database access, and other shared network applications that are common to network applications that are common to business uses. business uses.

• VLANs are a natural solution for this type VLANs are a natural solution for this type of traffic because you can segment users of traffic because you can segment users by their functions or geographic area to by their functions or geographic area to more easily manage their specific needs.more easily manage their specific needs.

Types of VLANsTypes of VLANs - - Network Network traffic type (8)traffic type (8)• Scavenger ClassScavenger Class

• The Scavenger class is intended to provide less-The Scavenger class is intended to provide less-than best-effort services to certain applicationsthan best-effort services to certain applications. .

• Applications assigned to this class have Applications assigned to this class have little or no little or no contribution to the organizational objectivescontribution to the organizational objectives of the of the enterprise and are typically entertainment enterprise and are typically entertainment oriented in nature. oriented in nature.

• These include These include peer-to-peer media-sharing peer-to-peer media-sharing applicationsapplications (KaZaa, Morpheus, Groekster, (KaZaa, Morpheus, Groekster, Napster, iMesh, and so on), Napster, iMesh, and so on), gaming applicationsgaming applications (Doom, Quake, Unreal Tournament, and so on), (Doom, Quake, Unreal Tournament, and so on), and any entertainment video applications.and any entertainment video applications.

VLAN Switch Port (1)VLAN Switch Port (1)• Static VLANStatic VLAN - Ports on a switch are manually assigned - Ports on a switch are manually assigned

to a VLAN. to a VLAN. – Static VLANs are configured using the Cisco CLI. Static VLANs are configured using the Cisco CLI. – This can also be accomplished with GUI management This can also be accomplished with GUI management

applications, such as the Cisco Network Assistant. applications, such as the Cisco Network Assistant.

• Dynamic VLANDynamic VLAN - This mode is not widely used in - This mode is not widely used in production networks.production networks.– A dynamic port VLAN membership is configured using a special A dynamic port VLAN membership is configured using a special

server called a VLAN Membership Policy Server (VMPS). server called a VLAN Membership Policy Server (VMPS). – With the VMPS, you assign switch ports to VLANs dynamically, With the VMPS, you assign switch ports to VLANs dynamically,

based on the source MAC address of the device connected to based on the source MAC address of the device connected to the port. the port.

– The benefit comes when you move a host from a port on one The benefit comes when you move a host from a port on one switch in the network to a port on another switch in the switch in the network to a port on another switch in the network-the switch dynamically assigns the new port to the network-the switch dynamically assigns the new port to the proper VLAN for that host.proper VLAN for that host.

VLAN Switch Port (2)VLAN Switch Port (2)

• Voice VLANVoice VLAN - A port is configured to be in voice - A port is configured to be in voice mode so that it can support an IP phone attached to mode so that it can support an IP phone attached to it. it.

• It is assumed that the network has been configured It is assumed that the network has been configured to ensure that voice traffic can be transmitted with to ensure that voice traffic can be transmitted with a priority status over the network. a priority status over the network.

• When a phone is first plugged into a switch port When a phone is first plugged into a switch port that is in voice mode, the switch port sends that is in voice mode, the switch port sends messages to the phone providing the phone with messages to the phone providing the phone with the appropriate voice VLAN ID and configuration. the appropriate voice VLAN ID and configuration.

• The IP phone tags the voice frames with the voice The IP phone tags the voice frames with the voice VLAN ID and forwards all voice traffic through the VLAN ID and forwards all voice traffic through the voice VLAN.voice VLAN.

Controlling Broadcast Domain Controlling Broadcast Domain (1)(1)

Controlling Broadcast Domain Controlling Broadcast Domain (2)(2)

Layer3 forwarding (1)Layer3 forwarding (1)

Layer3 forwarding (2)Layer3 forwarding (2)

VLAN Trunk (1)VLAN Trunk (1)

• A trunk is a point-to-point link between one or A trunk is a point-to-point link between one or more Ethernet switch interfaces and another more Ethernet switch interfaces and another networking devicenetworking device, such as a router or a , such as a router or a switch. switch.

• Ethernet trunks carry Ethernet trunks carry the traffic of multiple the traffic of multiple VLANs over a single linkVLANs over a single link. .

• A VLAN trunk allows you to extend the VLANs A VLAN trunk allows you to extend the VLANs across an entire network. across an entire network.

• Cisco supports Cisco supports IEEE 802.1QIEEE 802.1Q for coordinating for coordinating trunks on Fast Ethernet and Gigabit Ethernet trunks on Fast Ethernet and Gigabit Ethernet interfaces. interfaces.


Without VLAN trunking


With VLAN trunks

VLAN Trunk - 802.1Q Frame VLAN Trunk - 802.1Q Frame tagging (1)tagging (1)

• The VLAN tag fieldThe VLAN tag field consists of an consists of an EtherType EtherType field, a tag control information field,and the field, a tag control information field,and the FCS fieldFCS field. .

• EtherType fieldEtherType field– Set to the hexadecimal value of 0x8100. Set to the hexadecimal value of 0x8100. – This value is called the tag protocol ID (TPID) This value is called the tag protocol ID (TPID)

value. value. – With the EtherType field set to the TPID value, With the EtherType field set to the TPID value,

the switch receiving the frame knows to look for the switch receiving the frame knows to look for information in the tag control information field.information in the tag control information field.

VLAN Trunk - 802.1Q Frame VLAN Trunk - 802.1Q Frame tagging (2)tagging (2)• Tag control information fieldTag control information field

– 3 bits of user priority3 bits of user priority - Used by the 802.1p - Used by the 802.1p standard, which specifies how to provide standard, which specifies how to provide expedited transmission of Layer 2 frames. expedited transmission of Layer 2 frames.

– 1 bit of Canonical Format Identifier (CFI)1 bit of Canonical Format Identifier (CFI) - - Enables Token Ring frames to be carried Enables Token Ring frames to be carried across Ethernet links easily.across Ethernet links easily.

– 12 bits of VLAN ID (VID)12 bits of VLAN ID (VID) - VLAN identification - VLAN identification numbers; supports up to 4096 VLAN IDs.numbers; supports up to 4096 VLAN IDs.

• FCS fieldFCS field– After the switch inserts the EtherType and tag After the switch inserts the EtherType and tag

control information fields, it recalculates the control information fields, it recalculates the FCS values and inserts it into the frame.FCS values and inserts it into the frame.

VLAN Trunk - 802.1Q Frame VLAN Trunk - 802.1Q Frame tagging (3)tagging (3)

VLAN Trunk –Native VLAN VLAN Trunk –Native VLAN (1)(1)• Tagged Frames on the Native VLANTagged Frames on the Native VLAN

• Control traffic sent on the native VLAN Control traffic sent on the native VLAN should be should be untaggeduntagged. .

• If an 802.1Q trunk port receives a tagged If an 802.1Q trunk port receives a tagged frame on the native VLAN, it frame on the native VLAN, it dropsdrops the the frame. frame. – Consequently, when configuring a switch port on Consequently, when configuring a switch port on

a Cisco switch, you need to identify these a Cisco switch, you need to identify these devices and configure them so that they do not devices and configure them so that they do not send tagged frames on the native VLAN. send tagged frames on the native VLAN.

VLAN Trunk –Native VLAN VLAN Trunk –Native VLAN (2)(2)• Untagged Frames on the Native VLANUntagged Frames on the Native VLAN• When a Cisco switch trunk port receives untagged When a Cisco switch trunk port receives untagged

frames it forwards those frames to the native VLAN.frames it forwards those frames to the native VLAN.• The default native VLAN is VLAN 1. The default native VLAN is VLAN 1. • When you configure an 802.1Q trunk port, a default When you configure an 802.1Q trunk port, a default

Port VLAN ID (PVID) is assigned the value of the Port VLAN ID (PVID) is assigned the value of the native VLAN ID. native VLAN ID.

• All untagged traffic coming in or out of the 802.1Q All untagged traffic coming in or out of the 802.1Q port is forwarded based on the PVID value. port is forwarded based on the PVID value. – For example, if VLAN 99 is configured as the native VLAN, For example, if VLAN 99 is configured as the native VLAN,

the PVID is 99 and all untagged traffic is forward to VLAN the PVID is 99 and all untagged traffic is forward to VLAN 99. 99.

– If the native VLAN has not been reconfigured, the PVID If the native VLAN has not been reconfigured, the PVID value is set to VLAN 1. value is set to VLAN 1.

VLAN Trunk –Native VLAN VLAN Trunk –Native VLAN (3)(3)

Configuring VLANs and Configuring VLANs and Trunks Trunks

Configuring VLANs (1)Configuring VLANs (1)

Configuring VLANs (2)Configuring VLANs (2)

Configuring VLANs(3)Configuring VLANs(3)

Configuring VLANs(4)Configuring VLANs(4)

Verifying VLAN (1) Verifying VLAN (1)

Verifying VLAN (2)Verifying VLAN (2)

Verifying VLAN (3)Verifying VLAN (3)

Managing Port (1) Managing Port (1)

Managing Port (2)Managing Port (2)

• Delete VLANsDelete VLANs

• Alternatively, the entire vlan.dat file can be Alternatively, the entire vlan.dat file can be deleted using the command deleted using the command delete delete flash:vlan.datflash:vlan.dat from privileged EXEC mode. from privileged EXEC mode.

• After the switch is reloaded, the previously After the switch is reloaded, the previously configured VLANs will no longer be present. configured VLANs will no longer be present.

• This effectively places the switch into is This effectively places the switch into is "factory default" concerning VLAN "factory default" concerning VLAN configurations.configurations.

Configure a Trunk (1)Configure a Trunk (1)

Configure a Trunk (2)Configure a Trunk (2)

Verify a Trunk (2)Verify a Trunk (2)

Managing a Trunk (1)Managing a Trunk (1)

Managing a Trunk (2)Managing a Trunk (2)

Common problems with Common problems with trunkstrunks

Native VLAN MismatchesNative VLAN Mismatches (1)(1)

Native VLAN Mismatches (2)Native VLAN Mismatches (2)

Trunk mode mismatches (1)Trunk mode mismatches (1)

Trunk mode mismatches (2)Trunk mode mismatches (2)

Incorrect VLAN List (1)Incorrect VLAN List (1)

Incorrect VLAN List (2)Incorrect VLAN List (2)

VLAN and IP subnetVLAN and IP subnet

virtual lan (vlan) w.lilakiatsakun. vlan overview (1) a vlan allows a network administrator to...

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