Troubleshooting practice labs — Page 2

STP 10: Spanning Tree Troubleshooting Capstone

Advanced Rapid-PVST+ troubleshooting on a 3-switch triangle with a real Layer-2 loop. Two deliberate faults are seeded: an unintended root bridge wins VLAN 100 due to a mis-set/default priority, and PortFast/BPDU Guard are mistakenly applied on an inter-switch trunk. Two Alpine hosts in VLAN 100 verify user impact. Your job: use show commands to diagnose, then restore the correct root and remove edge features from the trunk while preserving them on access ports.

CCNA & CCNP70 min5 objectives

DHCP Troubleshooting Capstone: Branch Relay

Advanced CCNA troubleshooting capstone for centralized DHCP across a relay. A centralized IOS-XE router (DHCP-SRV) serves the branch LAN behind BR-RTR via ip helper-address. The lab imports in a deliberately broken state: the DHCP pool scope and gateway are misconfigured on the server, and the relay configuration is missing on BR-RTR. Learners must diagnose using show outputs and Linux tools, fix all three discrepancies, and verify that two Alpine clients dynamically receive usable leases and can reach DHCP-SRV.

CCNA65 min5 objectives

NAT Troubleshooting Capstone: Interface Role + ACL

Advanced NAT capstone, run as a fault hunt. Inside hosts cannot reach the internet, the translation table stays empty, and one host cannot even reach its own gateway. The lab is called NAT, which is the trap: not every fault here is a NAT fault. You get symptoms and the required end state — no fault list. Faults span the router, the switch and the path beyond, and fixing the translation alone will not restore service.

CCNA65 min5 objectives

Static Route Next-Hop Types: Recursive, Direct & Fully-Specified

Hands-on static routing lab in a small branch–WAN–branch triangle. You will configure recursive, directly-attached, and fully-specified static routes to enable end-to-end reachability between two hosts across three routers. You will learn how next-hop resolution works, how it appears in show ip route, and how to troubleshoot when static routes don’t resolve or forward as expected.

CCNA60 min4 objectives

ACL Troubleshooting Capstone: Classic Faults, NAT, Placement

Advanced ACL and NAT capstone, run as a fault hunt. A branch site was cut over last night and the policy does not behave: the flow that should be blocked gets through, other traffic does not come back at all, and nobody recorded what changed. You get symptoms and the required end state — no fault list. The faults span all three routers and include a shadowed ACE and a policy applied on the wrong side of NAT, so translated addresses hide the very hosts the rules name. Expect fixing the first one to change the symptom rather than clear it.

CCNA75 min5 objectives

OSPF Network Types: DR/BDR, Broadcast vs P2P

Hands-on CCNP OSPF lab comparing broadcast and point-to-point network types. Three routers share a multi-access Ethernet via an access switch to observe DR/BDR election, manipulate interface priorities, and then convert to point-to-point. Includes a user LAN behind R1 and realistic troubleshooting: neighbor stuck in 2-Way due to type mismatch, area mismatch isolating a router, and incorrect interface priority preventing desired DR/BDR roles.

CCNA & CCNP85 min6 objectives

Router-on-a-Stick Troubleshooting Capstone

Advanced CCNA capstone: diagnose and repair a fully-broken three-VLAN router-on-a-stick deployment. One iol-xe router uplinks by 802.1Q trunk to a pure layer-2 ioll2-xe switch, with three alpine PCs on their own access VLANs (10 Sales, 20 Voice, 30 CCTV); after a recent switch and router change, inter-VLAN connectivity is broken or intermittent across all three VLANs. Trace VLAN intent end-to-end from each host through the trunk to the router's subinterfaces, repair whatever faults you find, and verify with end-host pings/traceroutes and IOS show commands.

CCNA68 min5 objectives

Diagnosing a Broken Router-on-a-Stick

Advanced CCNA troubleshooting lab on a router-on-a-stick design. VLAN 10 users can reach their gateway and other hosts, but VLAN 20 users cannot reach their gateway or any resources in VLAN 10. Methodically trace L2/L3 intent end-to-end - from the access ports through the trunks up to the router subinterfaces - to isolate the first-hop failure and implement fixes that restore inter-VLAN routing while maintaining enterprise trunk hardening and clean configurations.

CCNA60 min5 objectives

802.1Q Trunking Troubleshooting Capstone

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.

CCNA55 min5 objectives

CCNA Capstone: Port Security Troubleshooting

Advanced CCNA port-security troubleshooting on a pure Layer-2 design. Two access switches linked by an 802.1Q trunk carry a Users VLAN across closets. Three Alpine Linux hosts are pre-addressed. The lab is intentionally shipped with multiple classic faults: one access port is err-disabled due to a prior port-security shutdown, one user-facing port lacks port-security altogether, another has the wrong violation mode and an overly restrictive maximum, and one port has an incorrect static secure-MAC configured. Your job is to diagnose using show commands, restore connectivity, and implement the intended security posture with sticky MACs, the correct maximum, the proper violation mode, and errdisable auto-recovery—without placing port-security on the trunk.

CCNA55 min6 objectives

CCNA Static Routing: Redundant Branch Triangle

Build a 3-router triangle with two branch LANs and real Alpine clients. Deploy primary static routes via the hub and floating backup statics over a direct branch-to-branch link. Verify reachability, path selection, and failover by simulating a hub outage.

CCNA65 min5 objectives

CCNA Port-Sec 9: Multi-Port Sticky Restrict Policy

Advanced CCNA switchport port-security rollout on multiple access ports across two Layer-2 switches with a trunk. You will standardize a consistent edge policy (sticky MAC learning, maximum 1, violation restrict) on all host-facing access ports while leaving the uplink trunk exempt from port-security. Includes a realistic drift on the trunk allow-list and VLAN database to fix before validating end-to-end user VLAN transport. Pure Layer-2: no SVIs or routing.

CCNA58 min6 objectives

Static Routing Between Branches Through an HQ Hop

Deploy IP addressing and bidirectional static routing across a three-router topology to connect two branch LANs through an HQ hop. Practice verification from end hosts, analyze routing tables, and troubleshoot asymmetric reachability.

CCNA45 min5 objectives

IPv4 Addressing Fundamentals: Interfaces, Gateways & Reachability

Beginner CCNA lab focusing on IPv4 addressing and basic Layer 3 verification on a small branch network. You will assign IP addresses to router interfaces, confirm end-host default gateways, and verify connected reachability using host-based pings. You will also learn to read 'show ip interface brief' and 'show ip route' to confirm operational state before any routing beyond directly-connected networks is configured.

CCNA50 min5 objectives

Troubleshoot a Branch ROAS: VLANs, Trunks & Port Security

Deploy and troubleshoot VLANs, 802.1Q trunks, and port security in a realistic small-branch ROAS design. You will stand up VLANs 10/20/99 with a hardened trunk native VLAN 999, configure sticky port security on access ports, correct a misassigned VLAN, and resolve an err-disabled port caused by a port security violation. Finish by verifying end-to-end host connectivity across VLANs.

CCNA55 min5 objectives

Standard ACL: Permit Host & Subnet, Deny Others

Beginner CCNA ACL lab on a compact 5-node CML-Free topology. You will configure static routing end-to-end, implement source NAT (PAT) at the source edge, and then build a standard numbered ACL near the destination to allow a single NATed host and a specific subnet while denying all others. You will validate with pings from end hosts, observe ACL hit counters and NAT translations, and troubleshoot common mistakes such as ACL placement, wildcard masks, and pre-/post-NAT address matching.

CCNA55 min7 objectives

Free with an account

CCNA: Named ACLs & Editing by Sequence Number

Hands-on ACL practice using named standard and extended ACLs, applied with correct placement and direction, edited by sequence number, and verified with counters and end-host tests. The lab adds a realistic NAT edge to expose order-of-operations pitfalls without obscuring data-plane ACL effects.

CCNA75 min6 objectives

ACL Segmentation Policy on Multi-LAN Router

Deploy and verify multiple IPv4 ACLs on a single router that terminates three distinct LANs (Client, Server, and Management). You will place an extended ACL inbound on the Client interface to allow only specific services to the Server and block access to Management, a standard ACL outbound on the Management interface to enforce destination-side protection by source, and a VTY access-class to restrict router SSH to the Management subnet only. Validate with end-host tests that permitted flows succeed while denied flows are provably blocked, and use ACL hit counts and logs to troubleshoot.

CCNA70 min5 objectives

ACL Wildcard Masks: Match Host, Subnet, and Range

Hands-on CCNA ACL practice using standard ACLs and wildcard masks to allow a single host, a contiguous range, and an entire subnet while proving a deny. You will place the ACL near the destination, order statements correctly, verify with end-host pings and ACL counters, and troubleshoot common mistakes.

CCNA55 min5 objectives

Multi-VLAN Segmentation: 3 VLANs & Trunk Alignment

Hands-on CCNA campus switching lab with two Layer-2 switches and three VLANs (Users 10, Servers 20, Management 99) extended over a single 802.1Q trunk. Learners deploy VLANs and access ports, harden the trunk (native VLAN 999, explicit allow-list, nonegotiate), and validate isolation. The lab ships with a trunk-carried outage: VLAN 10 traffic reaches its gateway successfully, but VLAN 20 traffic does not. You will diagnose from end hosts, confirm switch states, and correct the trunk so that same-VLAN traffic to the gateway SVI succeeds while inter-VLAN forwarding remains absent.

CCNA75 min5 objectives

Native VLAN & Trunk Mismatch: Detection and Recovery

Configure VLANs and 802.1Q trunks across two access switches with a router-on-a-stick gateway. Intentionally misconfigure the native VLAN and trunk allow-list to observe loss of intra-VLAN connectivity, detect the mismatch using switch warnings and show commands, and then remediate to restore user reachability. Validates VLAN segmentation, trunking symmetry, and troubleshooting skills for CCNA candidates.

CCNA65 min5 objectives

VLAN Troubleshooting Capstone: Native Mismatch & VLAN Drift

Advanced CCNA L2 troubleshooting in a compact branch. Some PCs can't reach their default gateway or other departments across two switches and a router-on-a-stick gateway, and your monitoring system has flagged a switching/trunking problem on the path. Validation is performed from the endpoints (Alpine hosts) using pings and ARP, and trunks are hardened with a non-default native VLAN.

CCNA65 min6 objectives

CCNA: VLAN DB & Trunk Allow-List Drift Recovery

Hands-on CCNA VLAN lab: build VLANs with names, assign access ports, harden and verify 802.1Q trunks, and troubleshoot a broken allow-list that prevents a VLAN from traversing the SW1–SW2 trunk. Includes router-on-a-stick gateways, management VLAN, and end-host validation.

CCNA65 min7 objectives

CCNA Static Routing: Troubleshooting Broken Static Routes

Hands-on CCNA static routing troubleshooting in a realistic three-router core/edge topology with two user LANs. Static routing on the network was recently changed and users at SITE-A (10.10.10.10) and SITE-B (10.30.30.10) can no longer reach each other; you will investigate the routers' route tables and next-hop reachability to diagnose and restore full bidirectional connectivity.

CCNA55 min5 objectives