Very Strange issue caused by FFS checks for new version AND fails to connect online.

[gdhm]

Hi Zenju :)

I cannot believe what has started happening because its SO strange.

Two days ago when I opened FFS it said it could not make a connection to check whether a new version is available. Weird I thought so I used my usual shortcut URL for this site and could not make a connection (either via Firefox or IE 11.
I then checked site on http://www.isitdownrightnow.com/. It said Up no issues.
I did pings via command line - Access OK.
I then tried a proxy and got through to the site.

I then rebooted PC but it did not help.
I then switched off my modem and tried accessing the site via Firefox SUCCESS. I repeated and no issues in either Firefox or IE11. OK I thought just one of those strange one off issues WRONG!!!

I then ran FFS and it came up with the message it could not connect/check for updates.
I thought, "How can this be the case I can get into site". I tried accessing the site again via Firefox and to my shock I no longer could.

I then tried FFS 8.0 but that did not cure issue and to be honest FFS 8.5 has been behaving itself completely each day until yesterday.

Today I did a more extensive test on what is going on. It is 100% the case on my win 10 Pro (x64) PC that I can get into the FFS site 100% of the time via Firefox or via IE11 PROVIDED I have not run FFS with "Check for updates weekly" ticked or having done a manual check via FFS.
If they are UNTICKED so FFS does NOT check for anew version of FFS then I can always and every time access this site.
BUT
IF I do a FFS manual check or automatic one then the check fails 100% of the time AND I then 100% of the time cannot access this site via any Browser (except via a Proxy browser).

I confirm 100% of the time after failure to connect if I switch modem Router off and on again. I can always access this site as normal.

I have tried IP flushing DNS flushing but those do not work. It seems something FFS does or calls adjusts something which so far only switching my modem off and on again solves.
I am not knowledgeable about Web connections etc. so I cannot understand what the issue is, or how to test further or resolve. All I do know is that this only started happening 2 days ago and my findings are 100% consistent.

No other of the many website I have tried to access during the last 2 days has failed, so this issue is down purely to FFS checking for a new version (well on my PC anyway).

Hoping you can help Zenju.
In the meantime I have unticked check for updates weekly and will not do any manual checks.
If by any chance you are at a total loss on what is happening then please can I ask you how I can stop the message in the FFS Menu Bar "= A new version of FreeFileSync is available: * Unknown *" from appearing when I have unticked checking for update

Many thanks

UPDATED OBSERVATION (possibly Red Herring) incident just as I was about to post I got a low memory warning on my PC. Art the time FFS was open and I had done a check. This happened 2 weeks ago on 2 occasions and NEVER since. I did track down the issue or a reaction of an issue to "IP Helper" which was one component service of a group group (Local Host:Local System (14). When I disabled it 2 weeks ago the memory usage stopped its continuous increase. THIS TIME same thing when switched off my Modem the memory massively reduced after a few seconds. Could there be a connection between the two issues?
I honestly cannot recall whether two weeks ago I had been using FFS but I do run FFS daily and sometimes more often.

[Smasher]

I have the same problem, checked on 6 different pc's.

And 2 different locations.

[gdhm]

I have the same problem, checked on 6 different pc's.

And 2 different locations.

Thanks for your input Smasher. I'm relieved I'm not the only one. That does not mean I am happy have the same issue Smasher, but your additional info hopefully will help trace and resolve the cause.

May I ask whether you too have Win 10 Pro (x64)? I ask as there is always a chance with Win 10 that a recent update may be involved (not that I can see how when only one site and application affected).

[Smasher]

Yes, windows 10 on all computers. BUT there have not been any updates, the last couple of days.

There's windows patchday today, but not installed yet.

[gdhm]

Until today's updates (one being a large cumulative update) the same applied to me. No updates in days.

Off topic for this issue but to help as you have mentioned today's patches, Smasher and it may help you and/or others.
I HAVE installed today's updates BUT the "Cumulative Update for Windows 10 Version 1607 for x64-based Systems (KB3194798)" failed to download fully first time and I had to trigger it again. It took a very long time DOWNLOADING (not installing),staying on certain percentages for long periods before moving on (41% being one). Then when it got to 81% it just stopped downloading completely. I waited 25 mins to see if it would continue but it did not. I decided to shutdown PC and Reboot. This time when I clicked on look for updates it found the 81% already there and continued and fully installed successfully. (I note on Web some users are finding the download fails at 99% and it rolls back what it had done. Luckily for me this did not happen. Certainly MS seems to be going downhill with its patches and updates and pre testing.

After I had finished I decided to do a C Drive Disk Clean-up and remove old superseded system updates. It reported there was 3.99TB (YES TB) of files to be cleaned out. Going on to the Web it seems Win 10 is prone to such misreporting (first time for me) and many actually mention being told 3.99TB from clean ups months ago. ANYWAY it cleaned as it should with no apparent issues.

[Zenju]

It looks like the web hoster has had some temporary issues lately. I wasn't able to access the website myself, then some time later everything is working fine again.
I do not see any errors or downtimes in the website hosting stats, so I suspect some weird DNS server issue. This also matches with your observation that you were able to make a connection via a proxy and also on my end I was able to access the web page just fine until I cleared the browser cache and were denied access for some time.

[Smasher]

The website works fine.
But when ffs check for updates, an error occurs, and the entire Lan network can not access the website.

I think it's some kinds of dns error, too.

Cause you can still access the website, from VPN, mobile network etc.

[Zenju]

I've seen such an issue with some flaky DNS server already like a year ago. It should be easy to test: If you are not able to access freefilesync.org, temporarily change the DNS server to 8.8.8.8 (Google's DNS) and see if this fixes the problem. In any case, I fear there is nothing one could do about this.

[Zenju]

I just was not able to access the website for 20 min, testing from multiple devices, no ping went through (not even directly for the site IP), changing DNS server did nothing. So it looks more like an issue with the web hosting rather than DNS.

[gdhm]

Hi Zenju :)

I have my DNS always set to 4 options and 8.8.8.8 is the first priority before trying the others.

The primary salient facts for me are I can get into this site 100% of the time whenever I have tried during the last 3 days UNTIL I do either a Manual update check for updates (or FFS does an automatic one on being run (which fails to connect every time its attempted. After that, I IMMEDIATELY cannot get into the site via my browsers no matter how long I wait UNTIL I switch my Modem OFF/ON. Then I can get into this site every time IMMEDIATELY afterwards PROVIDED I do NOT allow FFS to do another update check.

Whatever is the cause, it seems clear to me that the FFS update check does something different or triggers something that now upsets the modem's settings AND/OR stops the site accepting the connection attempt.
MAYBE the FFS update check is blocked by the sites security and the IP address is blocked thereafter. I say this because the one other thing switching off/on the Modem is that changes my dynamic IP address each time, (of course using a Proxy browser it will use a different IP address anyway so that MAY explain why only a proxy can access the site when other browsers cannot access cannot (after an FFS update check has been done AND not needing the Modem to be switched off/on first).

I have tried other app updates from within their apps and all connect and their sites are all accessible afterwards. It seems "all road lead to Rome" (namely FFS update checking & FFS site).

One final observation Zenju. Your others links in about and Help all work OK and do not affect access to site. In the case of the Help that actually links to your FFS site and does not affect access afterwards. ONLY the UPDATE checking cause the issue.

Regards, gdhm

[Zenju]

I've contacted web hosting support: they have no errors somewhere in their logs and also no clue what else to check. Great. I think the update check is a red herring, since there is no technical difference to what a web browser does. As always there has been no change on FFS's side.

[Zenju]

More observations: I was somehow able to trigger the web access error doing an update check from multiple VMs. After that I'm not even able to access freefilesync.org with my phone which is a totally unrelated device...except, it uses the same WLAN. => disconnected the phone from WLAN, can access freefilesync.org, connected WLAN, website not accessible again. So I went on the router and had it assigned a new IP and voilà, all devices can access freefilesync.org now. If this wasn't incidental, then it looks almost as if freefilesync.org is blocking the IP. Strangeness.

[Zenju]

After more testing it seems to be indeed IP-related. Does getting a new IP fix the problem for you as well? (maybe it's time to find a new web hoster)

[BuddyThePoodle]

Hi from the UK. I've been having the same problem since yesterday. The first I knew about it was when I opened the program and the message came up. Then I couldn't get to the web site through Internet Explorer. I'm using a British ISP and haven't changed any DNS settings from their standard ones.
The same thing happened on another of my PCs tonight although I was able to get to your site from the link on the FreeFileSync page on Sourceforge and then navigate around your site with no problems.

I few weeks ago, I passed on an old NAS drive to a local charity and suggested that they try FreeFileSync. I was told later, that when they tried to download it, they were told that the software was unsafe by their antivirus software. A member of staff tried again on his own PC with different antivirus software and got the same sort of response. I don't know whether this is because of the "bonus" software in the installation process or what. haven't had anything from my antivirus software, Bitdefender yet. It's probably not relevant but I just wondered whether there's any possibility that your IP address is being blocked on some DNS servers because of this?

[gdhm]

After more testing it seems to be indeed IP-related. Does getting a new IP fix the problem for you as well? (maybe it's time to find a new web hoster)

Hi Zenju ;)

Thanks for your continued investigating. My suspicion in my last post about IP address blocking after a FFS update check is increasingly looking like I was on the right track. Happy you no longer feel the FFS update checking is a Red Herring as I was not suggesting FFS app was to blame just that it was single trigger to the issue.

As you already know in my case, a new IP address DOES resolve issue until/unless FFS app is allowed to check of an update

One clue for your Host to consider is: What have they changed their end in the last 7-10 days maximum as only during the last few days has this issue occurred and I use FFS daily or more and very rarely miss a day). As you said FFS has not changed or been updated since the last update around 17th Sep 2016). My PC, OS, Modem, ISP have not changed for a long time, SO all that remains (subject to the realms of reasonability) is the HOST FFS uses, having changed something. (despite their logs).

A question you may be able to answer Zenju is:
Why the FFS app URL link https://freefilesync.org/manual.php?topic=freefilesync from via FFS F1 key or Menu option Help> View Help does NOT cause a block of IP address OR future connections to this site BUT whatever "Check for New version > ...two check options IIMMEDIATELY does. What are the differences? I feel that if possible that is the investigation direction to go.

If current reason cannot be resolved then maybe these checking options need a different method to check for a FFS update that can defeat or bypass whatever the HOST is inadvertently doing. I appreciate this suggestion probably much easier for me to suggest, than for you to program, even if possible (sorry).

Kind Regards

[Zenju]

After wasting countless hours with level-1 support it seems at least clear that the web hoster is blocking IPs and that this is responsible for the misbehavior. Getting more info about this is like pulling teeth, so the internal rules to this blocking have not been shared and were only indirectly acknowledged at all.
Meanwhile I can reliably reproduce the IP block, but it's not simply the FFS update check. It must come from inside a VM, at least in my case to trigger the blocking. I'm not aware that the update check is doing something special, but I'll check the code. If this doesn't help I'll have to switch hosting.

[gdhm]

Thank you so much Zenju for your (as usual) fast and dedicated support to issues raised.
I have looked up VM on the Web as not very techie and am still unsure what the VM reference means in relation to this issue, but obviously you do and that's what is important.

Certainly if the reference is to Us users using VM on our PCs then all I can advise is that with my Win 10 Pro (x64) PC I have not set up any VM activities myself, nor am I using any other OS or Emulators.
However IF FFS, Aomei Backupper or some other app I have installed is or Windows 10 itself uses VM activities then I would not be aware of this, due to my lack of knowledge. Anyway not important I personally understand :)

with regard to " I'm not aware that the update check is doing something special, but I'll check the code."
I am sure it is doing what it always has done Zenju, but there must be something different to a normal URL link to site (as used for Help) because the Host is identifying some difference (be it tiny) that is now triggering a block the FFS check-up attempt and also blocking the IP address based on that difference as a result. However the Host is not blocking access to the site's Help page when attempted from within the FFS app.
I can understand why you are bemused, as I am sure your method of update checking is similar to that used huge numbers of apps (not to mention your method has never been blocked during the years I have used FFS until a few days ago).

Best wishes

[Zenju]

I've identified a parameter that I am using which is triggering the IP block. The only difference this makes is a "Connection: Keep-Alive" in the HTTP packet. There is no logical reason why this minor difference should make the web hoster block the IP, but apparently it is.

[Zenju]

Just changed to a new webhoster! I think we're back in business! :)

Please let me know if the old issues are solved now or if new issues occur!

[gdhm]

Just changed to a new webhoster! I think we're back in business! :)

Please let me know if the old issues are solved now or if new issues occur!

Yes :) :) :)
ALL working as normal Zenju namely, checking via FFS connects and reports "FreeFileSync is up to date" message in menu bar has disappeared on a second running of FFS AND access to the FFS site works via my 2 Browsers afterwards.

Well done and thanks for all your efforts and speed of solution

Regards, Dave

[Smasher]

Yes, it's working again :)