Lab Simulation 25 Guidelines This is a lab item in which tasks will be performed on virtual devices. - Refer to the Tasks tab to view the tasks for this lab item. - Refer to the Topology lab to access

Lab Simulation 25: Voice/Data VLAN Configuration with LLDP --- Overall Goal The lab sets up two switches (Sw1, Sw2) to simultaneously support data traffic from PCs and voice traffic from Cisco IP phones on the same physical ports, then enables vendor-neutral neighbor discovery on

Submitted by alyssa_d· Mar 5, 2026Network Access

Question

Lab Simulation 25 Guidelines This is a lab item in which tasks will be performed on virtual devices. - Refer to the Tasks tab to view the tasks for this lab item. - Refer to the Topology lab to access the device console(s) and perform the tasks. - Console access is available for all required devices by clicking the device icon or using the tab(s) above the console window. - All necessary preconfigurations have been applied. - Do not change the enable password or hostname for any device. - Save your configurations to NVRAM before moving to the next item. - Click Next at the bottom of the screen to submit this lab and move to the next question. - When Next is clicked, the lab closes and cannot be reopened. Topology Tasks All physical cabling is in place and verified. Connectivity for the Switches on ports E0/1, E0/2, and E0/3 must be configured and available for voice and data capabilities. 1. Configure Sw1 and Sw2 with both VLANS, naming them according to the VLAN Name provided in the topology. 2. Configure the E0/1, E0/2, and E0/3 ports on both switches for both VLANS and ensure that Cisco IP phones and PCs pass traffic. 3. Configure Sw1 and Sw2 to allow neighbor discovery via the vendor-neutral protocol on e0/0. Answer: Task 1. Configure Sw1 and Sw2 with both VLANS, naming them according to the VLAN Name provided in the topology SW-1(config)#vlan 77 SW-1(config-vlan)#name User_VLAN SW-1(config-vlan)#exit SW-1(config)#vlan 177 SW-1(config-vlan)#name Voice_VLAN SW-1(config-vlan)#exit SW-2(config)#vlan 77 SW-2(config-vlan)#name User_VLAN SW-2(config-vlan)#exit SW-2(config)#vlan 177 SW-2(config-vlan)#name Voice_VLAN SW-2(config-vlan)#exit Task 2. Configure the E0/1, E0/2, and E0/3 ports on both switches for both VLANS and ensure that Cisco IP phones and PCs pass traffic. SW-1(config)#interface range E0/1-3 SW-1(config-if)#switchport mode access SW-1(config-if)#switchport access vlan 77 SW-1(config-if)#switchport voice vlan 177 SW-2(config)#interface range E0/1-3 SW-2(config-if)#switchport mode access SW-2(config-if)#switchport access vlan 77 SW-2(config-if)#switchport voice vlan 177 Task 3. Configure Sw1 and Sw2 to allow neighbor discovery via the vendor-neutral protocol on e0/0. SW-1(config)#lldp run SW-2(config)#lldp run

Exhibits

Explanation

Lab Simulation 25: Voice/Data VLAN Configuration with LLDP

Overall Goal

The lab sets up two switches (Sw1, Sw2) to simultaneously support data traffic from PCs and voice traffic from Cisco IP phones on the same physical ports, then enables vendor-neutral neighbor discovery on a specific port.

This is a classic voice/data convergence scenario. Rather than running separate physical cabling for phones and computers, Cisco switches use two VLANs on a single port: one for data, one for voice. The phone daisy-chains the PC through its built-in switch, and the switch separates traffic by VLAN.

Step 1 - Create and Name VLANs

vlan 77 / name User_VLAN
vlan 177 / name Voice_VLAN

Why necessary: VLANs must exist in the VLAN database before you can assign ports to them. If you skip this and jump straight to port configuration, the switch will either reject the VLAN assignment or create an unnamed VLAN - depending on the IOS version. Naming them (User_VLAN, Voice_VLAN) is required here because the exam grades the exact names from the topology.

What it accomplishes: Creates two isolated broadcast domains. VLAN 77 carries PC/data traffic; VLAN 177 carries IP phone traffic (typically tagged with CoS/QoS markings).

If skipped: Ports assigned to non-existent VLANs go into an inactive state. Traffic is dropped.

Step 2 - Configure Access + Voice VLAN on Ports E0/1-E0/3

switchport mode access
switchport access vlan 77
switchport voice vlan 177

Why switchport mode access: Explicitly sets the port as an access port (not a trunk). This is required before assigning a single untagged data VLAN. Without it, the port defaults to dynamic auto and may attempt to negotiate a trunk, which breaks the voice VLAN setup.

Why switchport access vlan 77: Assigns untagged frames (from the PC plugged into the phone's passthrough port) to VLAN 77.

Why switchport voice vlan 177: This is the key command for Cisco IP phones. It instructs the switch to:

Send CDP to the phone advertising VLAN 177 as the voice VLAN
Accept 802.1Q-tagged frames from the phone on VLAN 177
Apply QoS trust on those tagged frames

The port is technically still an "access" port from a data perspective, but it carries a second VLAN specifically for the phone using inline tagging.

Why interface range E0/1-3: Applies the configuration to all three ports simultaneously - more efficient and less error-prone than configuring each individually.

If skipped or out of order: If you set the voice VLAN before switchport mode access, the command may be rejected or silently ignored on some IOS versions. If you omit switchport voice vlan 177, phones will not receive their VLAN assignment via CDP and will either fail to register or send voice traffic over the data VLAN, degrading call quality.

Step 3 - Enable LLDP on e0/0

lldp run

Why this command: The task specifies a vendor-neutral neighbor discovery protocol. This is the key phrase - it means LLDP (Link Layer Discovery Protocol), not CDP. CDP is Cisco-proprietary; LLDP is the IEEE 802.1AB standard that works across multi-vendor environments.

lldp run enables LLDP globally on the switch. By default, Cisco switches run CDP but not LLDP.

Why only e0/0: The task scopes LLDP to e0/0. You could also use interface e0/0 + lldp transmit / lldp receive to limit it to that port, but enabling it globally (lldp run) satisfies the requirement since e0/0 will then participate. The exam answer uses the global command, which is simpler and correct.

If skipped: Neighbor discovery on e0/0 would only function via CDP, which non-Cisco devices cannot use. Any vendor-neutral device on that port (e.g., a non-Cisco switch or router) would not appear in show lldp neighbors.

Memory Tips

Concept	Mnemonic
Voice VLAN command	"voice goes on the phone, access goes on the PC"
LLDP vs CDP	"LLDP = Link (neutral/standard), CDP = Cisco (proprietary)"
Order matters	Create VLAN -> Assign to port - you can't assign what doesn't exist
`lldp run` = global	One command enables it everywhere; then per-interface tuning is optional

Key exam trap: If a question says "vendor-neutral discovery protocol," the answer is always LLDP, never CDP. If it says "Cisco proprietary," it's CDP. The two are not interchangeable.

Topics

#VLAN Configuration#Voice VLAN#Switchport Access Mode#LLDP

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