Practise switch scenarios involving SW1, SW2, VLANs, trunk links, allowed VLAN lists and show interfaces trunk output.
Start Scenario PracticeA network engineer is troubleshooting an OSPFv2 adjacency issue between two routers connected via a VLAN trunk. R1 and R2 are in different VLANs but are connected through a Layer 2 switch. The engineer has configured 'ip ospf 1 area 0' on the subinterfaces. The adjacency forms but is stuck in INIT state. What is the most likely cause?
Explanation: The INIT state indicates that the router has received a hello packet from the neighbor but the neighbor has not seen its own router ID in the hello packet. This is often due to a mismatch in the OSPF network type or a unicast communication issue. In a VLAN trunk scenario, if the subinterfaces are not in the same VLAN, the routers may not be able to communicate at Layer 2. However, the most common cause is that the routers are using the same router ID, which causes the hello packet to be ignored because the router sees its own router ID in the neighbor list.
An engineer is troubleshooting a network where IPv6 hosts on VLAN 20 are unable to communicate with each other. The switch is configured with IPv6 First Hop Security features including Private VLAN (PVLAN) and IPv6 Source Guard. The hosts are in the same VLAN but cannot ping each other. What is the most likely cause?
Explanation: Private VLAN (PVLAN) on VLAN 20 isolates ports within the same VLAN, preventing direct communication between hosts on isolated ports. Even though the hosts share the same VLAN, PVLAN restricts traffic so that isolated ports can only communicate with a promiscuous port (e.g., a router uplink), not with each other. This directly explains why IPv6 hosts on VLAN 20 cannot ping each other.
A large enterprise network is experiencing intermittent IPv6 connectivity loss for hosts on VLAN 100. Router R1 has the following relevant configuration: interface GigabitEthernet0/0.100 encapsulation dot1Q 100 ipv6 address 2001:DB8:1:100::1/64 ipv6 nd raguard ipv6 nd prefix default ipv6 dhcp relay destination 2001:DB8:1:200::1 ! Router R2 shows: debug ipv6 dhcp relay output indicates that DHCPv6 requests from VLAN 100 are being relayed, but the server never receives the SOLICIT messages. What is the root cause?
Explanation: An IPv6 ACL applied to the interface can implicitly deny the relayed DHCPv6 traffic. The debug output shows that DHCPv6 requests are being relayed from R1, but the server never receives the SOLICIT messages, indicating that the relayed packets are being dropped before leaving the router. An implicit deny in an IPv6 ACL on the outgoing interface (or inbound on the next hop) would block the relayed DHCPv6 unicast traffic, while the local relay process still sees the original client messages.
Which THREE symptoms indicate a misconfiguration in a VRF-Lite deployment where two routers are connected via a trunk link and each VRF should have connectivity? (Choose THREE.)
Explanation: Common symptoms include: pings failing between devices in the same VRF across the link, missing routes in the VRF routing table, and the VRF interface showing up/down due to misconfiguration. The incorrect options: a default route in the global table is not a VRF-Lite symptom; high CPU is not specific to VRF-Lite.
A network engineer configures a DHCP snooping trusted port on a switch to allow a legitimate DHCP server. However, clients connected to untrusted ports on the same VLAN cannot obtain IP addresses. The DHCP server is reachable and the switch shows no DHCP snooping drops. Which is the most likely explanation?
Explanation: When DHCP snooping is enabled, the switch inserts the relay agent information option (option 82) into DHCP requests received on untrusted ports. If the DHCP server is not configured to trust or process option 82, it will discard these requests, preventing clients from obtaining IP addresses even though the switch reports no drops. This is the most likely cause because the DHCP server is reachable and the switch shows no drops, indicating the issue lies with how the server handles the relayed packets.
+2 more scenario questions available
Practice all SW1 and SW2 VLAN Trunking Practice QuestionsPractise switch scenarios involving SW1, SW2, VLANs, trunk links, allowed VLAN lists and show interfaces trunk output. These appear throughout the 300-410 and require you to apply your knowledge, not just recall facts.
Cisco doesn't publish an exact breakdown, but scenario-based questions (especially exhibit and command-output formats) make up a significant portion of the 300-410. Practicing each scenario type ensures you're ready for any format.
Yes. Courseiva provides free 300-410 scenario practice across all official exam domains. The platform includes scenario-based questions, command-output interpretation, topic-based practice, mock exams, and readiness tracking — no account required.
Launch a full SW1 and SW2 VLAN Trunking Practice Questions session with instant scoring and detailed explanations.
Start Scenario Practice →