GUIDES MEET PRACTICE
Clear networking guides and 68 CCNA browser labs. Learn the concepts, practice IOS-style commands, and check your work as you go.
One lab free. No account, installation, or hardware needed.
A browser simulation of selected IOS behavior. It does not run an IOS image.
EXPLORE THE LIBRARY
Models, addresses, and the basics that connect everything.
↗ 02Switching & VLANsBuild and troubleshoot Layer 2 networks.
↗ 03RoutingUnderstand forwarding decisions and paths.
↗ 04Security & accessExplore controls, authentication, and firewalls.
↗ 05WirelessFrom WLAN fundamentals to controller operations.
↗ 06Linux & toolsDiagnose and verify from the command line.
↗FREE FIELD REFERENCES
A free PingLabz account unlocks the Linux, ASA, BGP, and OSPF PDFs. Choose the guide you need and keep it close while you practice.
GO FURTHER WITH PRO
Pro unlocks 60 build labs, six troubleshooting labs, and the campus Mega Lab. Follow guided exercises, try IOS-style commands, and check your configuration as you go.
SELECTED READING
Keep learning
Semaphore UI as a single binary on the control node, pointed at the Git repo from part 24: a project, a vault key, two templates and a schedule. Real runs against six IOS XE devices, including a vault key that was silently ignored.
A plain Git server with a pre-receive hook as the CI gate: yamllint, ansible-lint and a check-mode run against six IOS XE devices before a push to main is accepted, then a deploy step. Two real rejections, one real change, and what --diff did not show.
One read-only playbook turns facts and parsed show commands from six IOS XE devices into an inventory file and page: hostname, image, interfaces, CDP neighbors, OSPF and BGP state. Plus the CDP noise from the management segment and how I filtered it.
One read-only playbook that audits six IOS XE devices, renders a dated Markdown and HTML report, survives an unreachable device, and runs from a systemd timer. With what I actually scheduled and what I removed afterwards.
A four-playbook IOS XE upgrade workflow run against six lab devices: pre-checks, a confirmed staging step with MD5 verification, a post-check that diffs against a snapshot, and a rollback. Plus the parts the lab image could not do.
One services and hardening standard pushed to six IOS XE devices, the failures check mode missed, five idempotency traps, real SNMPv3 tests, and what the lab couldn't prove about AAA and NTP.
A dry run with --check --diff on three IOS XE routers, the real run, and a second check. Then two lines check mode called changed that the router rejected as invalid input.
An edge ACL from one data model, pushed with ios_acls. The first version forgot BGP and the branch peer went down three minutes later. The fix, the hit counts from real traffic, and what overridden would have deleted.
Every access port gets a two MAC limit, restrict mode and aging from one data model. Then a test host tries four MAC addresses, three get dropped, and the check playbook catches the violations.
The root bridge was an access switch nobody picked. One data model now sets the root, portfast with BPDU guard and LACP uplinks, and a check playbook catches a wrong root or a missing bundle member.
Parse CDP and LLDP neighbors on every device, normalize the names, compare the links with an intended list and render a Markdown report plus a Mermaid drawing. A shut port shows up as a missing link, then clears after the fix.
One router at a time with serial: 1, a parsed health check after each, and a block/rescue rollback that stops the rollout. A hello timer change fails and rolls back on the first router, a cost change rolls clean, and a 1 second settle time produces a false pass.