VLAN Trunking (802.1Q)

Hands-on CCNA switching lab contrasting single-VLAN access ports with 802.1Q trunks. You begin with the inter-switch link configured as a plain access port, so only one VLAN reaches the router-on-a-stick gateway while the other cannot. You will diagnose the connectivity problem, convert the link into a properly hardened 802.1Q trunk, and validate that both VLANs regain access to their gateway.

Hands-on CCNA switching lab focused on the native VLAN and tagging behavior on 802.1Q trunks. Users in one VLAN currently cannot reach their peers across a switch-to-switch trunk; you will standardize the native VLAN away from VLAN 1 to a dedicated parking VLAN, diagnose and correct the trunk configuration, verify the untagged VLAN on both ends, and confirm same-VLAN host reachability across the trunk.

Diagnose and remediate a trunk misconfiguration between an access switch and a distribution switch so that same-VLAN hosts across two access switches can communicate end-to-end. Use CDP and trunk verification commands to investigate the fault and restore proper trunk operation, without introducing any Layer-3 routing.

Hands-on CCNA lab focusing on 802.1Q trunk allow-lists. Build a realistic three-switch campus with two user hosts in VLAN 10. First bring up trunks carrying all VLANs by default, then implement an explicit allowed VLAN list and prune a non-used VLAN. Intentionally remove VLAN 10 from one trunk to observe an outage, verify with Linux pings and IOS show commands, and restore service by fixing the allow-list. Reinforce native VLAN alignment and compare default vs explicit trunk policy.

Hands-on DTP negotiation and trunk hardening across a 3-switch path. You will observe dynamic trunking behavior (auto vs desirable), fix an allow-list drift that blocks user VLAN transport, and then harden the trunks to static with nonegotiate and a non-default native VLAN. End-to-end host reachability in the same VLAN proves success.

Build an end-to-end 802.1Q path across three Cisco IOS Layer-2 switches so VLAN 10 transports user traffic from an access port on the left switch to an access port on the right switch through a middle switch. Harden trunks (native VLAN 999, nonegotiate) and verify with show interfaces trunk. Then intentionally break the allow-list to see the outage and restore service.

Build a single 802.1Q trunk between two Layer-2 switches that correctly carries three VLANs with an explicit allow-list and a dedicated non-default native VLAN. Place hosts in Users (VLAN 10) across both switches and a server in Servers (VLAN 20). Verify that the trunk allows VLANs 10, 20, and 99, that the native VLAN matches on both ends, and that same-VLAN hosts communicate across the trunk. Then intentionally break and restore the configuration to practice troubleshooting trunk allow-lists, native VLAN alignment, and host VLAN placement.

An advanced CCNA switching lab focused on verifying 802.1Q trunks and diagnosing a silent VLAN after a switch refresh. The topology uses three layer-2 switches (a distribution switch between two access closets) and two Alpine hosts, and users in VLAN 20 at one closet cannot reach their VLAN 20 peers at the other closet across the trunk path. Learners use show interfaces trunk, show interfaces switchport, and show vlan brief to locate the break and restore predictable Layer-2 forwarding without adding any Layer-3 configuration.

Advanced CCNA switching capstone centered on restoring end-to-end VLAN 20 transport across three Layer-2 switches using 802.1Q trunks. The starter ships intentionally broken: after a simulated maintenance window, two Alpine hosts in VLAN 20 can no longer reach each other across the inter-switch trunks. Learners diagnose with show interfaces trunk, show interfaces switchport, and show vlan brief, then identify and correct the trunking faults in the right order and verify with host pings.