Wikipedia:Reference desk/Archives/Computing/2016 November 18

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November 18

RockBox

for install the RockBox to Sandisk Sansaclipplus What should I do? I placed1 the folder ".rockbox" in the player, but I think there should be a further drop or something similar?95.86.90.3 (talk) 10:55, 18 November 2016 (UTC)

Old downloaded images won't display in newly downloaded htm file

I have various webpages downloaded, during the past few years, in a folder together. I have Windows 7 on a home computer, use Internet Explorer.

I edit the pathname for IMG statements in each htm file, as needed, so the file's images will display in my folder (for ex., if it comes as IMG SRC="images\printer.gif" I will edit to IMG SRC="printer.gif"). It has always worked in the past, but this year (2016) I began having problems.

It often happens now that if I download a webpage and try to use an image in that file which did not download with the file, the image will not display. For example, suppose I discard the newly-downloaded image "printer.jpg" and try to use an older image printer.jpg that I already have in the folder. For some reason, the old printer.jpg will not display in the new htm file.
Any advice on how to fix this, or at least why it might be happening?

Note the following:
1. The old image printer.jpg continues to display in my older htm files.
2. If I convert the new printer.jpg into printer.bmp (and change the IMG statement accordingly), it will display in any htm file (new or old). (Why the difference, anyway?)
3. If I copy the code of the new htm file into a .txt file and then rename the .txt file as an .htm file, the images still don't display in the new, new htm file.
4. I don't get any clues from the nature of the webpages or images-- various types of both.
5. If I replace the old image (printer.jpg, say) with the new image of the same name, it displays in any htm file-- old or new. (But this is not convenient as I may prefer the old image). — Preceding unsigned comment added by 72.251.71.95 (talk) 10:51, 18 November 2016 (UTC)

Check paths and upper/lower-case writing. HTML and Linux are case-sensitive in filenames, Windows is not. Else, ceack browser settings for disabled loading of pictures. --Hans Haase (有问题吗) 15:20, 23 November 2016 (UTC)

OS X Sierra connecting to VPN, but not routing traffic over it

I have a Mac Mini, from which I often use the built in client to connect to my university VPN. Since updating it to Sierra, the system has been ignoring my apparently successful VPN connection for long periods (no visible errors, but my public IP address remains my local broadband one). It does eventually shift to using the VPN if I wait, but the time taken to do so appears to be getting longer. Yesterday it still showed the wrong IP after 90 minutes of VPN connection.

I already tried deleting and recreating both the VPN and my local wifi connection, which made no difference. Then I trashed my network preferences plist files and rebooted, which fixed it once but the problem returned the next day. Then I started flushing the routing table ("sudo route -n flush" in Terminal) which works but I have to do it every time. The hardware and the broadband connection are the same as when it worked normally on El Capitan, and software is up to date. Any ideas, other than formatting and reinstalling the whole system? 129.67.118.135 (talk) 15:01, 18 November 2016 (UTC)

Before you wipe the system - are you sure this is "incorrect behavior"? I think you might overestimate exactly what a VPN can, or should, be doing to your network traffic. Review Virtual private network and the documentation for your VPN software.

A VPN does not usually conduct "full tunneling," or routing of all network traffic through the VPN. This is a common misconception. The VPN simply provides an option to route traffic via the private network, which hardly guarantees that all traffic will be routed through the private network (let alone whether any traffic is even encrypted).

Check your VPN configuration to see if it permits a "full tunnel" mode. Consider using an SSH session to create a SOCKS proxy, and configuring your web browser and other services to use that tunnel.

What you are presently observing - split tunneling - means that some traffic doesn't use the VPN. This is normal, default, correct behavior for most VPNs - it just isn't what you apparently expected.

Nimur (talk) 15:23, 18 November 2016 (UTC)

The VPN is advertised as a way to be virtually on campus, across the board so that all connections use it and are safely encrypted, and its documentation mentions "the service does not allow split tunnelling by VPN clients". I've also never seen it do this before, either on older versions of OS X or on Windows, and flushing the routing table does force it to stop splitting (for as long as one VPN session lasts). So I'm fairly confident this isn't correct behaviour.

I'm using the built in Mac VPN client, and I can't see anywhere to choose the tunneling mode. I've never used a SOCKS proxy before, but happy to try. Apologies for my ignorance, but will that require any support from the university end, and can I automate it so it always gets created as the VPN connects? Or could I automate the routing table flush (immediately after successful VPN connection) instead, since that brings back the behaviour I want? 129.67.118.135 (talk) 16:16, 18 November 2016 (UTC)

Ok, it seems that based on your latest description, this is worth some further investigation. Let's put aside the SOCKS proxy plan (though you can research how to configure it if you wish: it requires an SSH server, which most universities can provide).

If this is really happening, is a true regression new in macOS Sierra, and affects a major institutional VPN like your university, an official bug report to Apple at https://bugreport.apple.com is worth filing. Capture a sysdiagnose, mark down the bug report number, and I'll try to make sure somebody follows up.

From the description so far, I don't have enough information to offer a solution - yet. But I find it strange that force-flushing the route tables does anything - let alone fixes your symptom - so that detail should be investigated.

Nimur (talk) 16:33, 18 November 2016 (UTC)