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.
Jaime
Latest posts — page 28
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.
OSPF Adjacency States: The 8-State FSM, Explained
All 8 OSPF neighbor states (Down, Attempt, Init, 2-Way, ExStart, Exchange, Loading, Full), what triggers each transition, and what to check when a neighbor is stuck.
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.
SD-WAN: What Is It? The 5-Minute Primer
SD-WAN in five minutes: what it is, what it replaces, the four-plane architecture, transport-independent overlays, and how it stacks against traditional MPLS WANs.
Enable IEEE 802.1X Authentication on Windows 11 (Manual + Group Policy)
How to enable IEEE 802.1X on Windows 11 wired adapters. Start the Wired AutoConfig service, configure the Authentication tab, push the same settings via Group Policy.
What is 802.1X Authentication? End-to-End Flow with Real show Output
How 802.1X authenticates a switch port from link-up to traffic flow. The three roles, EAPoL exchange, IOS XE config, host modes, and real show authentication sessions output.
OSPF vs BGP Redistribution: Which Protocol Wins Which Tie
When OSPF and BGP both know about the same prefix, who wins? A practical walkthrough of mutual redistribution, the admin-distance trap, and why BGP into OSPF needs a filter or it takes down your domain.
paid
Lab sec-10 - Wireless Security WPA2 vs WPA3 (Concept Lab)
The CCNA exam covers wireless security at a concept level. WPA2 has been the dominant Wi-Fi security standard since 2004; WPA3 (announced 2018) addresses several known weaknesses and is now mandatory for new Wi-Fi 6 certification. This lab
paid
Lab sec-09 - IPsec Site-to-Site Overview (Concept Lab)
IPsec is the suite of protocols that builds encrypted, authenticated tunnels across untrusted networks. Two routers at different sites establish IKE (Internet Key Exchange) sessions, derive crypto material, and then encapsulate IP packets inside ESP (Encapsulating Security Payload) headers. The
paid
Lab sec-05 - DHCP Snooping and Dynamic ARP Inspection
DHCP snooping watches DHCP traffic on a switch and builds a binding table of legitimate IP-MAC-port mappings. Dynamic ARP Inspection (DAI) uses that binding table to verify ARP packets: if an ARP claims an IP that does not