Snowflake bridge moved to a faster server – what to do if it doesn't connect

The Snowflake bridge was moved to a more powerful network server at 2022-03-16 16:51:35. This is the beginning of a plan to scale Snowflake to handle more users. If you notice Snowflake being faster in the past few days, this is why.

However, I made a mistake when I migrated the bridge. The cause of the problem is technical (more technical), but the short explanation is that I installed the wrong onion keys on the new server. I noticed the error and fixed the onion keys at 2022-03-18 03:21:45 (about 34.5 hours later).

The server having wrong onion keys does not create a security risk, but it may prevent you from connecting to the bridge. The symptom of the problem is that Tor Browser bootstraps to 95% and then makes no further progress.

  • If you used Snowflake before 2022-03-16 16:51:35, then you probably were not able to connect between 2022-03-16 16:51:35 and 2022-03-18 03:21:45, when the wrong onion keys were installed. It should work again now.
  • On the other hand, if you used Snowflake for the first time after 2022-03-16 16:51:35 and before 2022-03-18 03:21:45, then your Tor Browser cached the wrong onion keys, and you will not be able to connect now.

The error in the Tor log is:

[WARN] Problem bootstrapping. Stuck at 95% (circuit_create): Establishing a Tor circuit. (DONE; DONE; count 2; recommendation warn; host 2B280B23E1107BB62ABFC40DDCC8824814F80A72 at 192.0.2.3:1)

If your Tor Browser is bootstrapping to only 95% with Snowflake, you can fix the problem by deleting one file. The file to delete is:

platform path
linux Browser/TorBrowser/Data/Tor/cached-descriptors
windows Browser\TorBrowser\Data\Tor\cached-descriptors
macosx Contents/Resources/TorBrowser/Tor/cached-descriptors

Then restart Tor Browser. You can also re-download Tor Browser and start from a fresh installation; that will also work.

Here is a post that show the effect of the new faster bridge.

This is the raw bandwidth measurements of the old bridge and the new:

This is just the Tor bandwidth (exclusive of pluggable transport encoding overhead and other traffic on the host):

This is the estimated number of simultaneous users. About 75% of Snowflake users are from Russia, currently.