Day 26 - VLAN, Trunking Concepts and Configurations Flashcards
Without VLANs, a switch considers every port to be in the same what?
Broadcast domain
What type of VLAN is this based on the description below?
Configured to carry only user-generated traffic, ensuring that voice and management traffic is separated from data traffic
Data VLAN
What type of VLAN is this based on the description below?
All the ports on a switch are initially members of this VLAN. It’s ID is always 1
Default VLAN
What type of VLAN is this based on the description below?
This should be a dummy VLAN assigned to all unused switchports on a switch
Black hole VLAN
What type of VLAN is this based on the description below?
This VLAN serves as a common identifier on opposing ends of a trunk link. This VLAN isn’t used for any traffic the switched network unless legacy bridging devices happen to be present
Native VLAN
What type of VLAN is this based on the description below?
This VLAN is a means to access the management capabilities of a switch
Management VLAN
What type of VLAN is this based on the description below?
This VLAN carries IP voice traffic from an IP phone to a switchport
Voice VLAN
A __________ ___________ is an ethernet point-to-point link between an ethernet switch interface and an ethernet interface on another networking device, such as a router or a switch, carrying the traffic of multiple VLANs over a singular link
VLAN Trunk
When a frame is placed on a trunk link, information about the __________ it belongs to must be added to the frame. This is accomplished using IEEE __________ __________ __________
VLAN
802.1q frame tagging
This is a Cisco proprietary protocol that negotiates both the status of trunk ports and the trunk encapsulation of trunk ports
DTP (Dynamic trunking protocol)
Which trunking mode is this based on the description below:
The switchport periodically sends DTP messages to the remote port, advertising that it is in an unconditional trunking state
switchport mode trunk
Which trunking mode is this based on the description below:
The local switch port advertises to the remote switch port that it is able to trunk but does not request to go to the trunking state
switchport mode dynamic auto
Which trunking mode is this based on the description below:
The local switch port advertises to the remote switch port that it is able to trunk and asks the remote switch port to go to the trunking state
switchport mode dynamic desirable
Which trunking mode is this based on the description below:
The local port is considered to be in an unconditional trunking state. Use this feature when you need to configure a trunk with a switch from another vendor
switchport nonegotiate
This verification command will show all of the configured VLANs, their name, status and the ports configured in those VLANs
show vlan brief
What verification command will verify an interfaces VLAN assignment?
show interfaces {int} switchport
example: show interfaces gi1/0/11 switchport
What verification command would you use to see if trunking is operational
show interfaces trunk
Other than show interfaces trunk, what is another verification command to see if a trunk is working on a specific link?
show interface {int} switchport
Example: show interface gi0/1 switchport
VLANs can be in one of two states. What are those states?
active and act/lshut
To compare the allowed VLANs on a switch you need to look at the __________ of three lists of VLANs listed by the __________ __________ __________ command
Second
Show int trunk
What command would allow you to add an allowed VLAN to an allowed VLANs list?
switchport trunk allowed vlan add {vlan-id}
Example: switchport trunk allowed vlan add 10
What OSI Layer do VLANs live at?
Layer 2
What kind of traffic were VLANs designed to segment?
Broadcast traffic
VLANs segment the LAN into what?
Separate broadcast domains
How would you configure a range of interfaces from fa0/1 to fa0/5 to go into VLAN 10?
int range fa0/1 - 5
sw mode access
sw acc vlan 10
If you’re sending unicast traffic to a different subnet with both devices in VLAN 1 will the traffic make it there without a router?
No, unicast traffic between subnets still need a router to get to where it’s going
Scenario: You have 3 computers all connected to access ports on the same switch
PC1: 10.10.10.5/24
PC2: 10.10.10.6/24
PC3: 10.10.20.2/24
All 3 are in VLAN 1
If PC1 sends a ping to 10.10.10.255 will PC3 receive that broadcast traffic as well?
Yes, broadcast traffic, regardless of what subnet the device is in, will get forwarded out ALL ports on the switch if they’re in the same VLAN
What encapsulation mode is a VLAN Trunk configured in?
dot1q
When a switch receives a packet with a Layer 2 header Dot1Q VLAN tag for VLAN 299. What ports will it send that traffic out of?
Only ports configured in VLAN 299
How would you configure a trunk port for gi1/0/1?
int gi1/0/1
description Trunk Port
switchport trunk encapsulation dot1q (modern switches don’t require this command)
switchport mode trunk
Do Native VLANs have to match on both sides of a trunk to come up?
Yes
What is a full configuration for a Trunk Port to SW2 with a Native VLAN of 100 on int gi1/0/1?
vlan 100
name Native VLAN
int gi1/0/1
description Trunk to SW2
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk native vlan 100
If two switches are cabled together in the right circumstances they can negotiate a trunk using what?
DTP (Dynamic trunking protocol)
What is switchport mode dynamic auto?
A command that will form a trunk if the neighbor switch port is set to trunk or switchport mode dynamic desirable
This will form a trunk if the neighbor switch port is set to trunk, desirable or auto. Default on older switches.
sw mode trunk or switchport mode dynamic desirable
What verification command would you enter to check the administrative mode on a switchport?
show int {int} switchport
What two items would be in the Operational Mode of a show int switchport command?
It will show whether it’s a trunk or an access port
What 2 items would be in the Administrative Mode of a show int switchport command?
What trunking state the link is in - Dynamic Auto or Dynamic Desirable
An Access port is considered what type of port?
Untagged port
Do untagged packets contain a VLAN tag?
No
What is the default DTP mode on modern switches?
Switchport mode dynamic auto
This protocol allows you to add, edit or delete VLANs on switches configured as ‘servers’ and have other switches configured as ‘clients’ sync their VLAN database with the ‘server’
VTP VLAN trunking protocol
How do you configure a VTP mode server?
vtp domain {domain-name}
vtp mode server
How do you configure a VTP mode client?
vtp mode client
What verification command would you use to verify VTP?
show vtp status
What 3 types of InterVLAN routing are there?
Router with Separate Interfaces
Router on a Stick
Layer 3 Switch Routing
Assigning IP addresses on the router to an interface in the same subnet as other connected devices in the network and then tagging them on the switch in the proper VLAN as an access port is considered what type of InterVLAN routing?
Router with separate interfaces
For Router on a Stick to work the cable going from the Switch to the Router has to be a what?
Trunk port
What are the general steps to create a VLAN and have it configured for interVLAN routing and WAN routing to other sites?
- Create the VLAN
- Enable IP Routing
- Create the SVI and IP it w/ a subnet mask
- Configure the Layer 3 interface to have it be a no switchport and add an IP Address and add a subnet mask to it
- Include that Layer 3 interface and the SVI in a routing protocol or a static route
Either of these commands will form a trunk, if the neighbor switch port is set to trunk, desirable or auto.
switchport mode trunk
switchport mode dynamic desirable
Either of these commands will form a trunk, if the neighbor switch port is set to trunk or desirable.
switchport mode trunk
switchport mode dynamic auto
switchport mode dynamic desirable
With DTP, trunk will not be formed if both sides are set to what?
auto
__________ ports carry traffic for one specific VLAN
Access
What command will you enter to allow VLANs 50 and 120 only on the trunk port?
switchport trunk allowed vlan 50,120
What is the configuration to disable DTP
switchport nonegotiate
