If you have followed the configuration steps above and Negotiate authentication is not working, you can turn on verbose logging of the authentication process. This could help you find the cause of the problem. To enable verbose logging, use the following procedure:
Close all instances of Firefox.
Open a command shell, and enter the following commands:
export NSPR_LOG_MODULES=negotiateauth:5 export NSPR_LOG_FILE=/tmp/moz.log
Restart Firefox from that shell, and visit the website you were unable to authenticate to earlier. Information will be logged to /tmp/moz.log, and may give a clue to the problem. For example:
-1208550944[90039d0]: entering nsNegotiateAuth::GetNextToken() -1208550944[90039d0]: gss_init_sec_context() failed: Miscellaneous failure No credentials cache found
This indicates that you do not have Kerberos tickets, and need to run kinit.
If you are able to run kinit successfully from your machine but you are unable to authenticate, you might see something like this in the log file:
-1208994096[8d683d8]: entering nsAuthGSSAPI::GetNextToken() -1208994096[8d683d8]: gss_init_sec_context() failed: Miscellaneous failure Server not found in Kerberos database
This generally indicates a Kerberos configuration problem. Make sure that you have the correct entries in the [domain_realm] section of the /etc/krb5.conf file. For example:
.example.com = EXAMPLE.COM example.com = EXAMPLE.COM
If nothing appears in the log it is possible that you are behind a proxy, and that proxy is stripping off the HTTP headers required for Negotiate authentication. As a workaround, you can try to connect to the server using HTTPS instead, which allows the request to pass through unmodified. Then proceed to debug using the log file, as described above.