Let’s work through the problems you’re hitting with the Ubuntu 17.10 torrent announce requests step by step.

First Error: "you sent me garbage - id not of length 20" #

This error is straightforward: the BitTorrent protocol requires an explicit peer_id parameter in every announce request, and this ID must be exactly 20 bytes long (when URL-encoded, that translates to properly formatted 20 %xx segments). Your first request didn’t include a peer_id at all, so the tracker rejected it immediately.

Second Request: Truncated URL & Incomplete Info Hash #

Your second attempt included a peer_id but the URL was cut off. Even before that, there’s a critical issue with your info_hash:

• The info_hash you provided (%f0%7e%0b%05%84%74%5b%7b%cb%35%e9%80%97%48%8d%34%e6%86%23%d0) only has 19 URL-encoded byte segments. A valid info_hash must be exactly 20 bytes long (so 20 %xx segments total). This incomplete hash will cause the tracker to reject your request even if other parameters are correct.

Fixing the Announce Request #

To get a valid response from the Ubuntu tracker, make sure your request includes all required parameters with correct formatting:

• info_hash: Full 20-byte URL-encoded hash extracted from your Ubuntu 17.10 torrent file (double-check you didn’t truncate it)
• peer_id: A unique 20-byte identifier for your client (e.g., use a standard prefix like -UT1710- followed by random characters to make it unique, e.g., -UT1710-abcdefghijklmnopqr)
• port: The port your BitTorrent client is listening on (typically between 6881-6889)
• uploaded: Number of bytes you’ve uploaded so far (start at 0 if you haven’t uploaded anything)
• downloaded: Number of bytes you’ve downloaded so far (start at 0 initially)
• left: Number of bytes remaining to download (equal to the total size of the torrent when you start)
• compact: Set to 1 to request a compact, efficient peer list from the tracker

Example Valid Request #

Here’s what a properly formatted initial request might look like (replace the placeholder info_hash and left value with your actual torrent details):

http://torrent.ubuntu.com:6969/announce?info_hash=%f0%7e%0b%05%84%74%5b%7b%cb%35%e9%80%97%48%8d%34%e6%86%23%d0%xx&peer_id=-UT1710-abcdefghijklmnopqr&port=6881&uploaded=0&downloaded=0&left=1234567890&compact=1

Additional Checks #

If you still run into issues:

• Verify you can reach torrent.ubuntu.com:6969 (use ping torrent.ubuntu.com or telnet torrent.ubuntu.com 6969 to test basic connectivity)
• Double-check that all bytes in info_hash and peer_id are correctly URL-encoded as %xx
• Ensure your request URL isn’t truncated—all parameters need to be fully included

内容的提问来源于stack exchange，提问作者Stav Alfi