Nexus Port-Channels and LACP: Suspended Members
Why NX-OS rejects channel-group before feature lacp, how to read the port-channel flags legend, and what a suspended member actually means.
Networking
Vendor-neutral fundamentals that apply no matter whose box you are logged into. Addressing, encapsulation, the OSI layers in practice, and why the packet went where it did.
Latest posts — page 2
NX-OS Fundamentals: Your First Thirty Minutes on a Nexus
A practical orientation for your first console session on a Cisco Nexus: what the box is, what is turned on, which VRF you are in, and how to save it properly.
NX-OS vs IOS XE: What Changes on Your First Nexus
If you know IOS XE cold, most of NX-OS will feel familiar until it suddenly does not. Here are the six differences that bite on day one, with real Nexus 9000v output.
SD-Access Design Questions: Where Fabrics Fit and Where They Don't
Not every network should be a fabric. SD-Access is a genuinely powerful architecture, but it is also a big commitment - a controller, an identity service, compatible hardware, and a operational model your team has to learn. The most valuable
SD-Access Segmentation: Macro (VN) vs Micro (SGT)
Segmentation is the entire reason most organisations buy SD-Access. Not the automation, not the roaming - the ability to say "guests cannot reach the finance systems, IoT devices cannot reach each other, and contractors only touch the two applications
SD-Access Border Handoff: IP Transit, SDA Transit, and L2 Handoff
A fabric that cannot talk to anything outside itself is a very expensive island. The border node is how an SD-Access fabric connects to the rest of the world - the data centre, the WAN, the internet, another fabric - and
SD-Access Host Onboarding: From Port to Policy
An endpoint plugs into a port. Somehow, seconds later, it is in the right virtual network, carrying the right security group tag, with the right policy following it wherever it goes in the fabric. That "somehow" is host
SD-Access Fabric Roles: Edge, Border, Control Plane, and Fabric in a Box
An SD-Access fabric is not a pile of switches. It is a set of roles, and every switch in the fabric plays one or more of them. Understand the roles and the fabric makes sense; miss them and it
SD-Access Underlay: Manual vs LAN Automation
Before an SD-Access fabric can do anything clever - before LISP, before VXLAN, before a single policy - it needs one boring, rock-solid thing underneath it: an IP network where every fabric node can reach every other fabric node'
On-Prem vs Cloud Network Design: What ENCOR Wants You to Know
The workloads a network engineer connects have moved. Some are still in a data centre you can walk into; many are in a public cloud you will never see; most enterprises are somewhere in between, running both at once. Designing
High Availability Techniques: SSO, NSF, and Graceful Restart
A core router or switch reloading should not take the network down. In a well-designed high-availability platform, a supervisor can fail, or software can be upgraded, and traffic keeps flowing with barely a ripple. The technologies that make
Enterprise Campus Design: 2-Tier vs 3-Tier at CCNP Depth
Every campus network is some answer to the same question: how do you connect thousands of users to each other and the outside world, reliably, at a cost you can justify, in a way you can grow? The classic answers