I-Firefox Community Forum

Hello everyone,

We are currently investigating an issue where browsers are sending HTTP requests with Connection: close in the header during integrated Windows authentication (NTLM authentication) via SAML Service Provider (SP), leading to premature termination of the TCP connection.

This behavior occurs in the middle of the authentication process, preventing the NTLM authentication from completing and subsequently prompting for re-authentication.

We have observed the following browser behaviors:

Chrome and Edge: These browsers function without issues, communicating with Connection: keep-alive. Safari (macOS): Older versions of macOS with Safari exhibit the Connection: close behavior, leading to authentication failure. Newer versions of macOS with Safari work correctly with Connection: keep-alive. Firefox (macOS): Even on the latest versions of macOS, Firefox continues to attach Connection: close, resulting in authentication failure. Upon reviewing logs, we've identified that various browsers attach the Connection: close header during the NTLMSSP_NEGOTIATE request in the NTLM authentication sequence. Although this happens in an environment with a load balancer, we have confirmed that the load balancer is not modifying the header; rather, the client (browser) is adding it.

We would appreciate your insights into the conditions under which Firefox attaches Connection: close to HTTP requests, especially considering the differences across macOS versions and other browsers, addressing the following points:

Are there any known conditions or past cases where Firefox outputs Connection: close in an NTLM authentication environment via SAML SP? Given that older Safari versions show similar behavior, we are also considering if there's a common factor depending on NTLM authentication and browser version. What are the general heuristics, logic, or triggers for a browser to decide to "close" a connection or to attach Connection: close? We are particularly interested in cases that occur mid-authentication process. Could specific configurations (e.g., the combination of SAML and NTLM authentication, or the presence of an intermediate proxy/load balancer) potentially influence Firefox's Connection: close behavior? Are there any additional logs or debugging information we should collect from the Firefox client side to further pinpoint this issue? Any guidance or suggestions you could provide to help us resolve this problem would be greatly appreciated.

Thank you.

seit einigen Updatesversucht das System verschiedene Webseiten ohne Erfolg zu öffnen. Es erscheint keine Fehlermeldung, auch kein Abbruch wegen Zeitüberschreitung oder der Hinweis, dass der Server nicht erreichbar ist.

Whenever I load Firefox, for the first minute or so, or the first X attempts at loading (any) website, I just get "Can't connect to server" errors. Eventually it does connect and then has no more issues, unless I close the browser and open a new one, then the process begins again.

New Alienware laptop with a fresh windows 11 install.

Other browsers are working fine, this is isolated to this browser, on this device only.

Things I have tried:

All the suggestions in the connectivity help section Uninstalling Firefox > Deleting my profile data from laptop > Cleaning registry > Deleting anything else that searching for "mozilla" turned up > Clean install without logging into any profile or enabling sync or importing anything (somehow still knows there was a previous install though, just doesn't import anything)

Still the same results.

I've used Firefox for probably a decade now and I am truly loathed to have to move to Chrome, but if I can't find a solution this is just untenable. Any help would be much appreciated!

As of recent I increasingly have issues with accessing websites, those websites previously (yesterday) worked fine on Firefox. Version is 148.0 on Mac 26.3 (Apple M3 Silicon).

Now it has completely stopped working. Only websites using direct IP-address still work, all others fail with "Hmm. We’re having trouble finding that site.". Safari still opens the websites flawlessly.

Nothing has changed on the OS level or application level as no updates have been installed (no need, as everything is up to date). Antivirus is BitDefender with extension for Firefox enabled for already an extended time (year or so).

I tried disabling several dns.resolver settings as mentioned in https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can. No improvement whatsoever.

I quit firefox, removed the cache manually and restarted while starting a new test profile, so completely blank. Issue is still there.

DNS Servers on OS-level are correct.

Version 148 was installed last night evening and as such could be the reason for the failure since it is basically the only thing that changed.

I get a message that says I must log into this network before I can access the internet then I get another message that says the page isn't direct redirecting properly Firefox has detected that the server is redirecting the request for this address in a way that will never be complete the problem can sometimes be solved back calls by disabling or refusing to accept cookies. I have done neither. don't understand what happened I was browsing and all of the sudden I'm not I guess I may have to switch my browser?

My home desktop computer is asking for a network login to access the internet today, after FireFox crashed. I do not see anywhere to login. Please help. I have a Mini Mac. I am at a library as my internet is not working.

On a dual-stack network, with Windows tcpip6 ‘disabledcomponents’ parameter set to prefer IPv6, Firefox ignores this setting whenever an endpoint resolves both an IPv4 and a NAT64 address.

While monitoring traffic captured while connecting to sites in Firefox, if the initial DNS request for the site comes back with an IPv6 address only, the connection attempts from client’s IPv6 address to destination IPv6. If DNS answers come back with IPv4 and IPv6, the connection attempts IPv6 to IPv6. If DNS answers come back with IPv4 and a NAT64 address, Firefox doesn’t even attempt to connect to the NAT64 address, it immediately defaults to IPv4. I’ve tried disabling the IPv4 fallback setting which doesn’t change the behavior.

We’re running version 140.8.0esr. Is this behavior intended for Firefox? Is there a way to configure Firefox so it doesn’t ignore NAT64 addresses in dual-stack environments? The only way I found to force this was to completely disable the IPv4 stack on the client system’s NIC.

every time i launch Firefox, I get the banner prompting me to log in to network so i can access to the internet, i don´t understand it , cos I see that I am both logged in and connected to the net ?

I have a question (speculation) about having several Firefox based browsers installed on my Windows 64 PC.

I have a Windows 10, 64 Bit PC with 64 Gigs of RAM. I've always had a habit of installing several versions of Firefox based browsers - all to no avail. However, as of recent, I'm finding that my browsers begin to slow down substantially after 15 minutes or so of browsing - please read on.

Right now, I have the following 64 Bit Firefox based browsers installed on my PC - they are:

Firefox Waterfox Floorp Librewolf

I have quite a large amount of bookmarks saved, and I make sure all browsers have the same bookmarks.

I have a half dozen or so of add-ons, and have tried - from time to time - to uninstall various add-ons to see if they were the cause of the slow downs, but none of that made a difference.

For example, let's say I'm browsing for 15-30 minutes or so, and have a half dozen different tabs brought up. After awhile, things begin to slow down substantially such as delays in clicking on links and having it respond, or right clicking, etc. Browsing speeds slow down substantially also.

Here is what I then usually do:

1. Create a new tab and type in "about:memory" and click on the save memory command.

2. Go into settings and delete cache.

This normally does nothing to speed up things, and I find I have to just close out the browser, wait a few seconds, and bring it back up to things to get back to normal.

This has me speculating - "Could" it be that having a variety of Firefox based browsers with similar data conflict with each other in some strange sort of way" Or is it something else? I know that having a bunch of tabs up can deplete memory usage, but as I mentioned above, I have 64 Gigs of RAM and never had this issue before.

My SSD drive has 500 Gigs of storage, and only half is being used.

Any suggestions or recommendations would be truly appreciated.

Ben Herrmann Fuquay-Varina, NC

Hi,

Is there any way to disable Insecure connection warnings on forms? I already disabled these 2 flags as was advised in other post and relaunched Firefox but I still see warnings.

security.insecure_field_warning.contextual.enabled = False security.insecure_password.ui.enabled = False

Thanks