{
  "id": 3254928,
  "title": "An interactive introduction to the spanning tree protocol",
  "url": "https://urgent.news/2026/08/25/an-interactive-introduction-to-the-spanning-tree-protocol",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-08-25T12:06:16.000Z",
  "source": {
    "name": "Lobsters",
    "slug": "lobsters",
    "url": "https://vincent.bernat.ch/en/blog/2026-spanning-tree"
  },
  "original_language": "en",
  "account": "The spanning tree protocol (STP) prevents network loops when adding extra Ethernet cables to a three-day office event. It blocks just enough spare cables to create a loop-free tree, allowing Stan's clumsiness and Blobby's cable connections to coexist. This protocol was designed in the 1980s and has evolved into rapid (RSTP) and VLAN-aware (MSTP) versions. STP uses a complex state machine, timers, link state changes, and control frames (BPDUs) to eliminate network loops.\n\nRSTP converges to a tree from the root to each bridge, displaying the time taken to reach this state. By cutting links, you can see how the protocol finds alternate paths. The protocol runs in a browser using an open-source MSTPD implementation. Radia Perlman, who invented STP, described it as a \"graph more lovely than a tree\" with loop-free connectivity that spans all LANs.",
  "summary": null,
  "key_points": [
    "Spanning tree protocol prevents network loops",
    "RSTP and MSTP evolved from original STP",
    "Protocol runs in browser using open-source implementation"
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}