磁铁是否真的删除了Tracker服务器？

Question

Recently I have read some materials about Magnet and BT. People always says Magnet is better than BT because it doesn't need tracker servers.

But I still have some questions about this.

I found downloading a file by Magent needs some steps below:

1. You got a Magnet Link from some websites.
2. You got a BitTorrent File from someone's computer in the DHT network by the Magnet Link.
3. You download the file by the BitTorrent File.

There still is a BitTorrent File. So there still are Tracker Servers in the BitTorrent File. If the Tracker Servers are unavailable, the File can't be downloaded.

Is my understanding correnct?

Magnet is only used to store and get BT Torrent files more easily? Not used to replace BT?

Answer 1

trackers and magnet links are independent.

You can have a bittorrent swarm with or without tracker. They can use the DHT and peer-exchange to discover peers for instance.

Whether you join a swarm via a magnet link or a .torrent file does not affect how that swarm discovers other peers. You can use trackers with magnet links (using &tr= parameter).

Suggesting that "Magnet" (assuming you mean magnet links) is somehow different from "BT" (assuming you mean BitTorrent) is misleading. It's all BitTorrent. Magnet links is just a convenient way of joining swarms where the client effectively downloads the .torrent file for you, from other peers.