A network administrator is configuring switch ports connected to desktop environments where IP phones and workstations share a single physical Ethernet drop. The switchports are configured to handle untagged data traffic on VLAN 10 and tagged voice traffic on VLAN 20. Which of the following statements correctly describe Layer 2 switch forwarding and VLAN broadcast domain behavior in this setup? (Select TWO.)
- Untagged Ethernet frames entering the port are processed internally within VLAN 10.Answer
- Broadcast traffic originating on VLAN 10 is constrained to ports belonging to VLAN 10 and will not cross into VLAN 20 at Layer 2.Answer
- CHosts on VLAN 10 can communicate directly with hosts on VLAN 20 through standard Layer 2 switch forwarding without a Layer 3 routing device.
- DThe 802.1Q tagging process inserts VLAN identifier metadata directly into the Layer 3 IP header before Layer 2 framing.
- EIf a native VLAN mismatch occurs across an 802.1Q trunk link, all untagged traffic is automatically routed to its intended destination without potential security leakage.
Answer
Untagged Ethernet frames entering the port are processed internally within VLAN 10, and broadcast traffic originating on VLAN 10 is constrained to ports belonging to VLAN 10 and will not cross into VLAN 20 at Layer 2.
VLANs operate by logically partitioning a single physical switch into distinct Layer 2 broadcast domains. Untagged frames received on a port configured for a specific data VLAN are assigned to that VLAN's broadcast domain. Consequently, broadcast frames generated on VLAN 10 are forwarded only to ports assigned to VLAN 10, maintaining full isolation from VLAN 20.
Step-by-Step Solution
Key Concept
VLAN Broadcast Domain Segmentation and Layer 2 Frame Processing