Where We Finally Explain How OSPF Actually Chooses a Path—Without Math Trauma You’ve made it to Post 5—congratulations. At this point, you know more about OSPF than the average person knows about their own taxes. Now we finally lift the hood and look at the part of OSPF that actually makes decisions: SPF — the […]
SPF Algorithm: Dijkstra, the Network’s Reluctant Matchmaker Read More »
Because Nothing Says ‘Fun Weekend’ Like Memorizing LSA Types If you’ve made it this far in OSPF, you’re doing better than most.You’ve survived neighbor states.You’ve survived areas.Now it’s time for the part of OSPF that everyone pretends to fully understand during design meetings: LSAs — Link State Advertisements OSPF’s postal service, rumor mill, and gossip
LSAs Explained: The OSPF Postal Service Read More »
A Network Architect’s Guide to Keeping Your Link-State Zoo Organized Welcome to Post 3, where we talk about something near and dear to every OSPF architect’s heart:Keeping the network from becoming a flaming LSDB dumpster fire. image a meme where OSPF enters the chat Enter OSPF Areas—the protocol’s built-in organizational system.Think of areas as OSPF’s
Areas: OSPF’s Attempt at Keeping Chaos Contained Read More »
Welcome back to our OSPF adventure—where packets are polite, adjacencies are dramatic, and routers have the emotional range of a Shakespeare character arc. Today we’re tackling OSPF neighbor states explained the way architects actually experience them—from the first Hello to full adjacency and everything that breaks along the way. It has to talk to another
OSPF Neighboring: Making Friends the Link-State Way Read More »
If you’ve been in networking long enough, you’ve had that moment: staring at a topology diagram at 2 AM, trying to figure out why half your routers are “Init,” one is “ExStart,” and another has gone completely “Full” with the wrong neighbor like it’s speed dating. Welcome, my friend, to OSPF—the protocol that is equal
OSPF: Oh-So-Perplexing? Not Anymore. Read More »
Ever wonder how the massive organizations we rely on protect their entire digital kingdom from the bad guys? It all comes down to one crucial device: the firewall. It’s the unsung hero, the digital bouncer, and the grumpy gatekeeper all rolled into one. Think of it this way: to get into your home, a visitor
Stop That Fire! What Exactly is a Firewall and Why Your Network Needs One Read More »
Alright, here we are for part three of the EVPN Lab – BGP Configuration. In our last configuration post EVPN Lab – Multicast Configuration we setup multicast in the underlay. Now we get to configure BGP so when we get to the next video and we are setting up VXLAN and EVPN, we don’t have
EVPN Lab – BGP Configuration Read More »
Here we are! The official start of the long awaited EVPN Lab series! We are going to start out the EVPN Lab with OSPF Configuration. If you are having some doubts on your OSPF skills, you can head over to OSPF Basics for a quick refresher! What are we going to configure in this lab:
EVPN Lab – OSPF Configuration Read More »
Let’s take a trip down memory lane. I last learned about OSPF basics when studying for my ICND 2 exam in 2008. How do I know and or remember this? Well, 1, it was when I earned my CCNA, my first-ever associate Cisco certification. The more plausible answer is that I kept all my notes
When I say OSPF route filtering, I know what some of you think: “Mike, did you bang your head on something? LSDBs have to be consistent across the entire area for OSPF to calculate SPF properly, so how can you filter routes?” There are three ways to filter routes in OSPF, they are: Each of
OSPF Route Filtering Read More »