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.
4 min read
VLAN
Virtual LANs and Layer 2 switching, the foundation of every campus network. Articles tagged VLAN cover fundamentals, trunking, inter-VLAN routing, EtherChannel, troubleshooting, and campus design on Cisco Catalyst switches.
33 posts
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.
5 min read
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.
5 min read
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.
5 min read
Tagged vs Untagged VLANs: How Trunks and Access Ports Really Work
Tagged and untagged frames are the half of every VLAN problem nobody explains clearly. The mental model, when each is correct, the native VLAN, and the cross-vendor (Cisco / Aruba / Juniper) cheat sheet.
7 min read
VLAN Hopping Attacks Explained: Switch Spoofing and Double Tagging
VLAN hopping bypasses Layer 2 isolation. The two attacks (switch spoofing via DTP, double tagging via the native VLAN) and the four-line Cisco configuration that defeats both.
7 min read