HSRP States: The 6-State Machine with show standby Output
All 6 HSRP states (Initial, Learn, Listen, Speak, Standby, Active), what drives the election, why preempt matters, interface tracking, and real show standby output.
Latest posts — page 29
VLAN vs VXLAN: The L2 Overlay, Demystified
VLAN vs VXLAN explained: a VLAN tags L2 segments, VXLAN encapsulates them across L3. The 4,094 limit, VTEPs, BGP EVPN, and when you actually need VXLAN.
Cisco Catalyst SD-WAN: The Rebrand, the Architecture, OMP
Cisco Catalyst SD-WAN (formerly Viptela / Cisco SD-WAN): the naming history, the four-plane architecture, OMP routing, and the zero-touch edge onboarding flow.
How to Install Cisco CML 2.10 on VMware ESXi (Step-by-Step with Screenshots)
A step-by-step, screenshot-by-screenshot walkthrough of installing Cisco Modeling Labs (CML) 2.10 on VMware ESXi: deploy the OVA, size the VM, attach the refplat ISO, run setup, and start your first node.
QoS on a Router: A Practical Cisco IOS XE Walkthrough
How to build a working QoS policy on a Cisco router: MQC class maps, policy maps, the LLQ + CBWFQ model, and the shaper rule that makes it actually engage.
BGP Weight: The Cisco-Only Path Attribute (and When to Use It)
BGP weight is the first tiebreaker in the path-selection algorithm, set locally and never propagated. The three ways to set it, how it compares to LOCAL_PREF, and worked examples.
QoS for VoIP Across an MPLS WAN
End-to-end QoS for VoIP across an MPLS L3VPN: DSCP marking, the LLQ + CBWFQ policy at the CE edge, and the DSCP-to-MPLS-EXP mapping the carrier needs.
STP and EtherChannel: When They Collide and Who Wins
How EtherChannel hides bundled links from STP, the bundling protocols (LACP, PAgP, on), the dangerous failure modes, and why LACP active on both sides is the only safe configuration.
Inter-VLAN Routing: SVI vs Router-on-a-Stick (with Real IOS XE Config)
The two ways to route between VLANs on Cisco: SVIs on an L3 switch and router-on-a-stick. Real IOS XE config for both, the performance gap, and the gotchas.
MPLS L3VPN vs SD-WAN: When to Migrate
A decision framework for migrating from MPLS L3VPN to SD-WAN: what's different, when to migrate, the 7-step transition that works, and when the right answer is to stay.
BGP Looking Glass: What It Is, Public Servers, and Hosting Your Own
BGP looking glasses explained: what they show, the public servers worth bookmarking, a four-step troubleshooting recipe, and how to host your own with hyperglass.
VLAN, Subnet, and Broadcast Domain: What's the Difference?
VLAN, subnet, and broadcast domain are not the same thing. The layer each lives at, the relationships between them, and the misalignment that breaks hosts silently.