User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.5) Gecko/2008120122 Firefox/3.0.5 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.5) Gecko/2008120122 Firefox/3.0.5 The Troubleshooting Tools buttons added in FF3 are nice. I think an additional test for DNS problems should be included, indicating (a) whether DNS responded or not and (b) what the response was (ie. either the resolved IP or the error message returned) Many OS's and applications respond to DNS failures in strange ways that don't intuitively point the user to a problem with DNS... often firefox will just hang until DNS times out and give you an Address Not Found error. In other situations, the URL may resolved from a local cache, but if DNS has recently gone down subsequent lookups needed to render the main will timeout but not result in an Address Not Found error. It would be nice to know if this was because the server failed to resolve the addr (and why!), or if the DNS server didn't even respond. If it's the latter, it could be for a variety of reasons, but at least you have a better idea of where the problem lies. Reproducible: Always Steps to Reproduce: 1. 2. 3. Expected Results: An new "DNS" button among the other diagnostic tools buttons ("Ping Server", "Retry This", "Trace to Server", etc.). When clicked, a DNS request for the the host named in the URL would be sent (bypassing local cache), and the results would be shown, including DNS server name/IP, main result (eg. timeout, error, success), the IP address of the target host or the error message received from the DNS server (plus anything else that might be useful, such as a layman's interpretation and suggestions of what to do in each case.)

What Troubleshooting Tools ? Is this an extension ?

This is a mass search for bugs which are in the Firefox General component, are UNCO, have not been changed for 500 days and have an unspecified version. Reporter, can you please update to Firefox 3.6.10 or later, create a fresh profile, http://support.mozilla.com/en-US/kb/managing+profiles, and test again. If you still see the issue, please update this bug. If the issue is gone, please set the status to RESOLVED > WORKSFORME.

Comment 0 seems to be referring to an add-on, and even if it weren't, we're not likely to add the suggested DNS button to stock Firefox.