Hands-on Cisco IOS XE lab walkthroughs. Each lab ships with a real CML topology, configs you can paste, and verified show output. Articles tagged Labs cover the full CCNA 200-301 blueprint across Network Fundamentals, Network Access, IP Connectivity, IP Services, and Security Fundamentals.
Stop hand-editing pasted router configs. This post builds the full templating pipeline: YAML variables, a Jinja2 template, rendered CLI, and a Netmiko push to a live router, all captured from a real CML lab.
NAT, DHCP, and IP SLA faults rarely leave clues in show ip route. Five services ticket scenarios with the exact translation table, binding, or tracking object to check for each, grounded in real lab behavior.
DHCPv6 prefix delegation, general prefixes, and NPTv6: the IPv6 services engineers often skip, shown with real CML output of a delegated prefix flowing all the way to a downstream interface.
Embedded Packet Capture puts Wireshark-grade capture inside the IOS XE router itself: no SPAN, no capture laptop, no cabling. Includes a real on-router capture from a CML lab and the syntax difference that will bite you.
Build SNMPv3 in production form: users, groups, views, and the three security levels. The payoff is a real encrypted trap arriving and being decrypted on a Linux receiver, with no cleartext community strings on the wire.
The IOS DHCP server does far more than network, default-router, dns-server. This article covers options for PXE boot and phones, DHCP classes, and manual bindings, with real lease output from a CML lab.
Two customers with identical 10.5.5.0/24 subnets reach one shared exit through a single router. VRF-aware NAT on IOS XE keeps them separate, and this CML lab build shows two translation tables holding identical inside-local addresses.
Five MPLS L3VPN and DMVPN ticket scenarios, each isolated layer by layer: IGP, LDP, MP-BGP, NHRP, IPsec, and the routing on top. The faults and diagnostic commands come from real lab builds.
IKEv1 and IKEv2 configured on the same DMVPN in a CML lab, with real SA output shown side by side. The migration turns out to be a single-line profile swap, and you see exactly why IKEv2 negotiates faster.
A dual-hub DMVPN can black-hole spoke-to-spoke traffic for two hours after a hub fails because of one default timer. This post builds the design in CML, fails a hub, and shows exactly what breaks and how to fix it.
When two customer sites share an AS number, BGP loop prevention breaks their MPLS L3VPN on purpose. Reproduce the failure in a CML lab and fix it three ways: as-override, allowas-in, and SoO, with real output for each.
6VPE carries IPv6 L3VPN across an IPv4 MPLS core using the same VRFs, RTs, and MP-BGP sessions you already run. This article builds it in CML and shows the two-label stack that makes it work.