Cisco Wireless Access Point Modes Explained
Every Cisco AP mode explained: Local, FlexConnect, Monitor, Sniffer, Rogue Detector, SE-Connect, Bridge and Mesh. What each does and when to use it.
Fundamentals
Networking fundamentals and CCNA-level reference content. The TCP/IP and OSI models, ethernet basics, encapsulation, IPv4 addressing, layer 2 fundamentals, and the Cisco IOS commands every network engineer reaches for. The foundations beneath the pillar guides.
Latest posts — page 4
Segment Routing (SR-MPLS): Replacing LDP and RSVP-TE
SR-MPLS keeps the MPLS data plane and drops LDP and RSVP-TE. Prefix-SIDs, adjacency-SIDs, source-routed label stacks, SR-MPLS vs SRv6, and why networks migrate.
VTP (VLAN Trunking Protocol): v1, v2, v3 and Why It's Dangerous
How VTP propagates VLANs across a domain, the three modes, the revision-number disaster, v1/v2/v3 differences, and why many engineers disable it.
OSPF Passive Interface: What It Does and Where to Use It
OSPF passive-interface stops Hellos and adjacencies on an interface but still advertises its subnet. Config, the default pattern, and the route-filter gotcha.
EIGRP Neighbor Requirements: The 5 Things That Must Match
The 5 things that must match for EIGRP routers to become neighbors: subnet, AS number, K-values, authentication, and process membership. Plus what does NOT need to match.
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.
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.