Bad Checksum reported on all Updates

[bitman]

Hmmm, interesting, start with user selected preference, then make a random selection if that fails? Or add an option to use most recent successful server first.

Since at this point none of this logic exists, this idea is as good as any. The real problem, however, is download server bandwidth as mentioned by md usa spybot fan in the post he referenced above. Methods for reducing this load like incremental updates should probably be the first priority.

Unfortunately I don't know what the "bad checksum" error actually means... does it indicate a communication failure with an overloaded server, for example, that is "seen" as a result file that does not validate because it's missing some part? Feel like I need to understand more about the underlying cause to make sense of this.

As already mentioned, this can be due to any number of issues, not just the server itself. Since the initial SpybotSD.ini control file is downloaded from a different server, almost anything that can fail will cause this message. This is because the client has no way to determine what really failed, since the download takes place in the control of Windows, not Spybot. Spybot only gains control of the file at the point the download completes or fails due to timeout, so all it can do is check the file's integrity using the checksum, thus the Bad Checksum error message.

A Technique has already been discussed elsewhere of detecting a currently unavailable server by downloading a small file and verifying it's checksum, then switching to another (random or sequential) server if that fails. Adding additional 'smarts' to this would make sense, but the core problem is detection of a failed or more so a very slow responding server before attempting a large download such as the 1MB Includes (detections) file.

Until such major changes can be made to the Spybot program, it's best to choose the most effective server available. Though the two 'Safer Networking' servers in Europe are typically very fast, they may not be the most reliable due to a special case.

The 'BN FileForum (World)' is actually several servers placed in strategic locations around the world (4 in the US), so if one fails, others are already available to take over for the failed server. Even though these servers are often not the fastest (best bandwidth), especially in Europe or Asia/Pacific due to inefficient peering by local ISPs, they should be the most available.

Using the "Set this server as the preferred download location" with the BN FileForum (World) selection should result in the highest probablility of success. Since there are multiple servers worldwide and a failure is dealt with via network routing, it's designed to deal with the most likely failure scenarios, including some ISP peering or router failures.

[nexuswest]

Wanted to thank member DK2005 for posting a URL with an explanation of the cause. I had several replies in close sequence today, and missed this post that probably came in before I was asking about likely causes. Bottom line is "server busy", but the link is worth reading b/c S&D has answered that question clearly.

Again, thanks!!!

Robert