If there’s one thing that trips up engineers new to BGP, it’s the difference between eBGP and iBGP. Not because the concept is hard, but because the implications are sneaky. The sessions look the same. The commands are almost identical. But the behavior is different enough to absolutely destroy a network if you’re not paying
eBGP vs iBGP: A Field Guide to Not Confusing Yourself Read More »
Someone on your team suggested BGP. Or you read an article. Or you watched a conference talk where the speaker made it sound like BGP was the answer to everything. And now you’re wondering if your network actually needs it. For most networks, the answer is still no That’s not a knock on BGP, it
Do You Actually Need BGP? (An Honest Answer for People Who Hate Wasting Time) Read More »
Pour something good. This one’s worth it. Border Gateway Protocol, or BGP, has been running the internet since 1989. Your ISP uses it. Amazon uses it. Google uses it. The backbone of every packet that leaves your network and crosses into someone else’s depends on it. And there’s a decent chance you’ve been avoiding it
BGP: The Protocol That Runs the Internet (Whether You Like It or Not) Read More »
A Network Architect’s Guide to Diagnosing Problems Before They Become Resume-Generating Events Welcome to the grand finale.You’ve survived the theory, the design, the LSAs, the SPF math, and the war stories.Now it’s time for the part every network engineer eventually faces: Troubleshooting OSPF when it decides to set itself on fire at 2:13 AM. This
Troubleshooting OSPF Without Crying (Much) Read More »
Because Good OSPF Design Prevents 2 A.M. Phone Calls, Heartburn, and Existential Dread You’ve stuck with this series through neighbor states, areas, LSAs, and SPF algorithms.Now we get to the part where all that knowledge turns into real-world design wisdom—the kind you only gain from:• production outages,• painful migrations,• and explaining to leadership why OSPF
OSPF Design Tips: Lessons From the Field (and the Outages) Read More »
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 »