Tag: Architecture
-
The Server That Never Talked: ARP TTL, FDB Aging, and a Broadcast Storm
An ARP TTL FDB aging mismatch turned a data center into a light show. Around 2005, every top-of-rack switch in the data center was blinking like a light show at a disco rave. I traced the cause back to a server doing exactly what its owner designed it to do. The failure wasn’t a misconfiguration,…
-
1500 != 1500: MTU, OSPF ExStart, and a 14-Byte Blind Spot
What OSPF is actually doing when it stalls in EXSTART, why MTU is the non-obvious suspect, and what to check first when you hit it.