VLANs
A Virtual Local Area Network (VLAN) is an L2 segment of the network which defines a broadcast domain and is identified by a tag added to all Ethernet frames running within the domain. This tag is called a VLAN ID (VID) and can be assigned a value of 1-4094.
Each port can have a switch mode of either:
Access – access port is a port connected to a host. It can accept only untagged frames, and assigns them a default configured VLAN (Port VLAN ID). On egress, traffic sent from the access port is untagged.
Access-dcb – receives ingress untagged traffic but sends egress priority tag (VLAN ID = 0)
Hybrid – hybrid port is a port connected to either switches or hosts. It can receive both tagged and untagged frames and assigns untagged frames a default configured VLAN (Port VLAN ID). It receives tagged frames with VLANs of which the port is a member (these VLANs’ names are allowed). On egress, traffic of allowed VLANs sent from the Hybrid port is sent tagged, while traffic sent with PVID is untagged.
Trunk – trunk port is a port connecting 2 switches. It accepts only tagged frames with VLANs of which the port is a member. On egress, traffic sent from the Trunk port is tagged. By default, a Trunk port is, automatically, a member on all current VLANs.
Create a VLAN.
switch
(config) # vlan6
switch
(config vlan6
) #Change back to config mode.
switch
(config vlan6
) # exitswitch
(config) #Enter the interface configuration mode.
switch
(config) #interface
ethernet1
/22
switch
(configinterface
ethernet1
/22
) #From within the interface context, configure the interface mode to Access.
switch
(configinterface
ethernet1
/22
) # switchport mode accessFrom within the interface context, configure the Access VLAN membership.
switch
(configinterface
ethernet1
/22
) # switchport access vlan6
Create a VLAN.
switch
(config) # vlan6
switch
(config vlan6
) #Change back to config mode.
switch
(config vlan6
) # exitswitch
(config) #Enter the interface configuration mode.
switch
(config) #interface
ethernet1
/22
switch
(configinterface
ethernet1
/22
) #From within the interface context, configure the interface mode to Access.
switch
(configinterface
ethernet1
/22
) # switchport mode hybridswitch
(configinterface
ethernet1
/22
) #From within the interface context, configure the Access VLAN membership.
switch
(configinterface
ethernet1
/22
) # switchport access vlan6
Create a VLAN.
switch
(config) # vlan10
switch
(config vlan10
) #Change back to config mode.
switch
(config vlan10
) # exitswitch
(config) #Enter the interface configuration mode.
switch
(config) #interface
ethernet1
/35
switch
(configinterface
ethernet1
/35
) #From within the interface context, configure the interface mode to Trunk.
switch
(configinterface
ethernet1
/35
) # switchport mode trunk
Create a VLAN.
switch
(config) # vlan10
switch
(config vlan10
) #Change back to config mode.
switch
(config vlan10
) # exitswitch
(config) #Enter the interface configuration mode.
switch
(config) #interface
ethernet1
/35
switch
(configinterface
ethernet1
/35
) #From within the interface context, configure the interface mode to Hybrid.
switch
(configinterface
ethernet1
/35
) # switchport mode hybridswitch
(configinterface
ethernet1
/35
) #From within the interface context, configure the allowed VLAN membership.
switch
(configinterface
ethernet1
/35
) # switchport hybrid allowed-vlan add10
switch
(configinterface
ethernet1
/35
) #
For more information about this feature and its potential applications, please refer to the following community post:
vlan
vlan {<vlan-id> | <vlan-range>} Creates a VLAN or range of VLANs, and enters a VLAN context. | ||
Syntax Description | vlan-id | Range: 1-4094 |
vlan-range | Any range of VLANs | |
Default | VLAN 1 is enabled by default | |
Configuration Mode | config | |
History | 3.1.1400 | |
Example | switch (config) # vlan 10 | |
Related Commands | show vlan | |
Notes | Interfaces are not added automatically to VLAN unless configured with trunk or hybrid mode with “all” option turned on. |
name
name <vlan-name> Adds VLAN name. | ||
Syntax Description | vlan-name | 40-character long string |
Default | No name available | |
Configuration Mode | config vlan | |
History | 3.1.1400 | |
Example | switch (config vlan 10) # name my-vlan-name | |
Related Commands | show vlan | |
Notes | Name can not be configured for a range of VLANs. |
show vlan
show vlan [id <vlan-id>] Displays the VLAN table. | ||
Syntax Description | vlan-id | 1-4094 |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.1.1400 | |
Example | switch (config vlan | |
Related Commands | show vlan | |
Notes |
switchport mode
switchport mode {access | dot1q-tunnel | trunk | hybrid | access-dcb} Sets the switch port mode. | ||
Syntax Description | access | Untagged port. 802.1q tagged traffic are filtered. Egress traffic is untagged. |
dot1q-tunnel | Allows both tagged and untagged ingress Ethernet packets. Egress packets are tagged with a second VLAN (802.1Q) header. | |
trunk | 802.1q tagged port, untagged traffic is filtered. | |
hybrid | Both 802.1q tagged and untagged traffic is allowed on the port. | |
access-dcb | Untagged port, egress traffic is priority tagged. | |
Default | access | |
Configuration Mode | config interface ethernet | |
History | 3.1.1400 | |
3.3.4500 | Added MPO configuration mode | |
3.4.3000 | Added dot1q-tunnel parameter | |
3.6.6000 | Added ability to switchport mode for a range of interfaces | |
Example | switch (config) # interface ethernet 1/7 | |
Related Commands | show vlan | |
Notes | Switchport mode may be configured for a range of interfaces (interface <inf-type> <id-range> switchport mode <type>) |
switchport dot1q-tunnel qos-mode
switchport dot1q-tunnel qos-mode {pipe | uniform} Assigns QoS to the service provider’s traffic. | ||
Syntax Description | pipe | Gives the service provider’s traffic QoS 0 |
uniform | Gives the service provider’s traffic the same QoS as the customer’s traffic | |
Default | pipe | |
Configuration Mode | config interface ethernet | |
History | 3.4.3000 | |
Role | admin | |
Example | switch (config interface ethernet 1/1) # switchport dot1q-tunnel qos-mode uniform | |
Related Commands | show vlan | |
Notes |
switchport access
switchport access vlan <vlan-id> Configures the port access VLAN. | ||
Syntax Description | vlan-id | 1-4094 |
Default | 1 | |
Configuration Mode | config interface ethernet | |
History | 3.1.1400 | |
3.2.0500 | Format change (removed hybrid and access-dcb options). Previous command format was: “switchport {hybrid | access-dcb | access} vlan <vlan-id>”. | |
3.3.4500 | Added MPO configuration mode. | |
3.6.6000 | Added ability to configure VLAN ID for a range of interfaces. | |
3.7.1100 | Updated command syntax & notes. | |
Example | switch (config interface ethernet 1/7) # switchport access vlan 10 | |
Related Commands | show vlan | |
Note |
|
switchport {hybrid, trunk} allowed-vlan
switchport {hybrid, trunk} allowed-vlan {<vlan> | add <vlan> | remove <vlan> all | except <vlan> | none} Sets the port allowed VLANs. | ||
Syntax Description | vlan | VLAN ID (1-4094) or VLAN range |
add | Adds VLAN or range of VLANs | |
remove | Removes VLANs or range of VLANs | |
all | Adds all VLANs in available in the VLAN table" | |
except | Adds all VLANs expect this VLAN or VLAN range | |
none | Removes all VLANs | |
Default | N/A | |
Configuration Mode | config interface ethernet | |
History | 3.1.1400 | |
Example | switch (config interface ethernet 1/7) # switchport hybrid allowed-vlan all | |
Related Commands | show vlan | |
Note |
|
switchport voice
switchport voice vlan <vlan-id> Configures voice VLAN for the interface. | ||
Syntax Description | vlan-id | 1-4094 |
Default | Disabled | |
Configuration Mode | config interface ethernet | |
History | 3.6.1002 | |
Example | switch (config interface ethernet 1/7) # switchport voice vlan 10 | |
Related Commands | lldp med-tlv-select | |
Note |
show interfaces switchport
show interfaces [<if>] switchport Displays all interface switch port configurations. | ||
Syntax Description | if | Possible interface types:
|
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.1.1400 | |
3.6.6102 | Added ability to filter by specific interfaces and updated Example | |
Example | ||
switch (config) # show interfaces switchport
| ||
Related Commands | show vlan | |
Notes | This command can accept an explicit interface or interface range (displays information only for available interfaces) |