Hi,

Thank you for contacting support. I am sorry to hear that the internal websites are not loading, and there appears to be a web filter issue and a dns issue.

Please check to see if it persists on other browsers, then with the web filter if anything is blocking access.

References:

• Advanced panel - Accessibility, browsing, network, updates, and other advanced settings in Firefox
• Is it also working in another browser? Firefox can't load websites but other browsers can
• Troubleshoot your web filter and see if there are any rules blocking the internal sites, check with the web filter administrator of the network you are using.

Other references

• http://technet.microsoft.com/en-us/li.../cc961921.aspx
• https://help.ea.com/article/how-to-flush-dns-cache-for-windows /flushdns

Hello, I can confirm that ANY other browser operates correctly. This was stated in my original post. I do not believe it to be a web filter issue, as of course it is an internal site. So IE11/IE10, Safari 5.1.7 and Chrome 31.0.1650.63 m.

Hi bloomcomputing,

Thank you for posting back with your results. Another troubleshooting step you can take is creating a new profile. Please create a new profile and let us know if the issue continues.

Profile Manager - Create, remove or switch Firefox profiles

Sorry, this doesn't work either. My colleague on another computer receives exactly the same error. I can also replicate this error on many other computers across the school site.

Hi bloomcomputing,

Please check to see if firefox is being blocked from the school's domain name server. If it was working before, you can flush the dns cache on the computer /flushdns in the cmd.exe.

Firefox can't load websites but other browsers can

If you are using a proxy, by default Firefox uses the System settings to connect. These options are in Tools> Options > Advanced > Network > Connection [Settings...]

Please let us know if you are not using a proxy or how that goes, we are happy to help.

Following a little more investigation by myself yesterday, I did solve the issue. The server aforementioned is on a static IP, which is then defined as an exception in the system proxy settings. Other browsers are able to realise that the DNS name resolves to an IP within this range. Despite Firefox set to automatically pick these up, it does not realise the DNS name of the server translates to an IP in the range and so just times out. So it's definitely a bug with Firefox that needs to be resolved as like I said, other browsers are able to resolve the DNS and make adjustments to access the data. No doubt I am not the first to come across this issue.

Hi bloomcomputing,

Thank you for posting back I would be more than happy to file a bug for this issue. To make it an affective/complete bug, if you are ok with sharing troubleshooting information for the developers this will help a bunch!

Some effective information needed:

• Clear steps to reproduce (include the IP addresses if that's possible)
• Network log of the beginning of connection where this error occurs. If you open Tools --> Web Developer --> Network this console will allow you to collect the logs for the engineers to analyze.

So far the most likely bugs have been shared with me are: Are these related to your issue? if so I would put the information in a comment on those bugs

• https://bugzilla.mozilla.org/show_bug.cgi?id=408669
• https://bugzilla.mozilla.org/show_bug.cgi?id=148707

If not I can file a bug with the information in the component Firefox Core> Networking.

Thank you again, and we look forward to your post.

1. . Internet proxy settings set in Control Panel, with exceptions also noted for internal IPs, including that used for internal website.
2. . Browse to http://itserv/ in Internet Explorer, Google Chrome, Safari with no issues. Browser recognises that itserv translates to IP address within exception range and so loads page correctly.
3. . Browse to http://itserv/ in Firefox, and page times out and gives:

"Error The requested URL could not be retrieved Error: The web filter could not find the address for the requested site Why you are seeing this: The system is unable to determine the IP address for itserv " Note, if I use an IP address at this point it's also fine

1. . Add itserv into proxy exception list in Control Panel, so there is now the IP exception and DNS exception.
2. . Firefox opens page correctly, hooray!

I can confirm that the bugzilla posts are along the same lines as my issue, very surprised these still exist some 7 years on!

I am unable to export the network logs from Firefox, however it does show in the timings section that the 18ms used to process the request were only used on waiting.

_{edit formatted (Used # for numbered paragraphs. ) ~J99}

Hi bloomcomputing,

In order to export the HTTP traffic on the page you can follow MDN's posted instructions for HTTP logging. https://developer.mozilla.org/en-US/d.../HTTP_logging

Though I am happy to hear that it works!

Hopefully this log is helpful then. I admit I made a mistake in the middle adding an incorrect DNS name in the proxy exception list, so the first failed attempt it at the start, but the working attempt is near the end when trying to access itserv. If the upload of the .txt file doesn't work below, where do I send the log?

We can create a new bug or add more information to the bug below. If you login to bugzilla you have the option to upload the troubleshooting information there: https://bugzilla.mozilla.org/show_bug.cgi?id=408669

Just add the steps, a little information about the setup and systems you ran the test on.

If you are interested to find out more information about bugs:

• https://bugzilla.mozilla.org/page.cgi?id=etiquette.html
• https://quality.mozilla.org/docs/bugz.../how-to-write-a-proper-bug-part-2/