Answers: Data and Voice VLAN 1

By certskills June 4, 2016 09:10

Configure a VLAN? Easy. Configure both a voice and data VLAN on an access port? Not too hard. Make sure it all works in a small network? Yet another small step, all required learning on the path to being a network engineer and getting your CCENT and CCNA R&S certs. As usual, first read and attempt this lab, and then come back to this post for the answers.


Figure 1: Basic Switched IP Phone Topology

Example 1: Dist1 Config


Example 2: Dist2 Config


Example 3: Access1 Config


Example 4: Access2 Config



When working on a network that implements voice over IP, one of the common tasks to perform is to configure both a data and a voice VLAN on a single switch port. When configured in this way the switch access port acts like a trunk and tags voice traffic with an 802.1q tag. The IP phone is connected in line with the PC and will strip this traffic away to itself and pass all untagged traffic to the PC.

This lab tasks you to create two new VLANs, 10 and 20 and to assign all PCs into VLAN 10 and all IP phones into VLAN 20. But you also need to add those VLANs to the two distribution switches, because otherwise those distribution switches will not know of the existence of VLANs 10 and 20, and will not forward frames in those VLANs.

To create a VLAN, use the vlan vlan command in global configuration mode. Because all switches use VTP transparent mode, all four switches need this command to create each VLAN. Note that all four switches list both the vlan 10 command and the vlan 20 command.

Switch Access1’s G0/3 and G1/0 interfaces connect to PC1 and PC2 and their respective IP phones. To configure PC1 and PC2’s data VLAN use the switchport access vlan 10 command. To configure the voice VLAN to be used by the IP phones, use the switchport voice vlan 20 command. Similarly, switch Access2’s G0/3 and G1/0 interfaces connect to PC3 and PC4 and their respective IP phones, and so Access2’s ports use the same two commands to assign the data and voice VLANs.

Data and Voice VLANs 1
Syslog 1
By certskills June 4, 2016 09:10
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  1. Spontaneous September 21, 08:32

    Hi Wendell,

    I’m new this and currently studying for the ICND1,
    in this lab, for he PCs and IPhones to communicate do we not have to configure IP address on the Vlans?

    Reply to this comment
    • CCENTSkills September 22, 07:05

      Well, if the phone needed to send a packet directly to the PC, or vice versa, then some device would need to route packets: a router with ROAS config or a layer 3 switch. And in a real network, some device probably supports that routing. As written here, this lab didn’t ask for that part of the story. One reason for not including that is that normally the PC and phone wouldn’t send packets directly to each other. So when thinking of “how to configure a port to support a phone and connected PC”, it’s usually the config you see here, and not the config for routing between the subnets that the PC and phone happen to reside in.
      Hope this helps…

      Reply to this comment
  2. HectorJ November 30, 20:35

    The use of vlan’s on distribution switches is not mentioned on CCENT/CCNA ICND1 100-105 book. Actually, because of the way vlan’s creation is explained, seems like it (a vlan creation on a switch) is because of the existence of some port in such a vlan. I think that it would be great if this matter is explicitly mentioned on next issues. Thanks in advanced

    Reply to this comment
  3. HectorJ November 30, 23:02

    By the way, chapter 11 initial quiz of the CCENT/CCNA ICND1 100-105 book, asks this:

    Quetion #4:

    “Imagine that you are told that switch 1 is configured with dynamic auto parameter for trunking on its Fa0/5 interface, which is connected to switch2. You have to configure switch2. Which of the following settings for trunking could allow trunking to work? (Choose two answers)”
    Proposed answers are:
    a. On
    b. dynamic auto
    c, dynamic desirable
    d, access
    e. None of the other answers are correct

    And, according with what is printed on the book, answers are:
    a and c.
    That is: “on” and “dynamic desirable”.
    Unless I missed something “on” is just a status to show that negotiation of trunking is “on”, but not a configurable parameter.

    What`s wrong with that?

    Reply to this comment
  4. Bav June 7, 03:15

    I think answer option a should read as “trunk” not “on”. Check the errata as I think that’s the 1st typo in the book.

    Reply to this comment
  5. Joel T February 21, 14:52

    on all trunk ports do you not need to add vlan 10/20 to the allowed vlan list? switchport trunk allowed vlan add 10 for example?

    Reply to this comment
    • certskills Author February 21, 17:32

      Hi Joel,
      By default, all VLANs are allowed in the allowed list, so there’s no need to add config for that.

      Reply to this comment
  6. Stefano B. August 26, 14:43

    Hi Wendell, because there is no need to change the Vlans names I think that for both Access1 and Access2 it would be acceptable (and faster) to omit the vlan 10 and vlan 20 commands. Vlans will be automatically created right after the switchport access vlan 10 and switchport voice vlan 20 commands. Please correct me if I am wrong. Besides, I wonder if it would be advisable to insert the switchport mode access command between these two commands.

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