Different Firefox behavior depending on DNS

Depending on the DNS server being used, when the user enters a single word into the Location Bar, sometimes Firefox will display "Did you mean to go to...?".

Why does this only happen with certain DNS servers, but not with others?

Wasn't Firefox changed to not make DNS calls on single word searches from the Location Bar?

Testing performed on Firefox v38.0.5.

RockPaperLizard

Posted 2015-06-30T20:49:35.607

Reputation: 5 415

firefox 38.0.5 No Did you mean to go tonotifications at all. – befzz – 2015-06-30T21:30:44.427

@befzz Thanks. If you try a few different DNS servers, some will cause Firefox to generate the notification. – RockPaperLizard – 2015-06-30T21:45:49.427

can you provide some magic words that cause to show notifications? and dns servers?(public google)? – befzz – 2015-06-30T21:48:27.673

@befzz Almost any random string consisting of at least 4 characters should demonstrate the issue. For example, abcd and efgh. – RockPaperLizard – 2015-06-30T23:58:04.093

there is an option in about:config browser.fixup.dns_first_for_single_words;true – befzz – 2015-07-01T00:27:05.313

@befzz Thanks! It was already set to false (which is now the default). Unfortunately, even with it set to false, it seems to make a DNS call. – RockPaperLizard – 2015-07-01T04:31:59.860

Answers

Searched and found this, while its for Chrome it should also apply for Firefox. Below is the original answer by "Ashi Krishnan". So its mostly caused by ISP's DNS and should disappear with a public DNS.

The problem is that your ISP is running a domain "helper" that responds in the affirmative to every server it's asked about. So when Chrome asks if 'tubes' exists, your ISP is saying, yes, I've got that right here. If you click on the omnibox, I strongly suspect that you'll be taken to a landing page owned by your ISP.

Chris.C

Posted 2015-06-30T20:49:35.607

Reputation: 1 038

Thanks Chris. Unfortunately, it sometimes happens with both private and public DNS servers. But the reasoning may be what the quote you provided claims. The odd thing is that, from what I have read, Firefox is no longer supposed to perform DNS lookups on single word searches from the Location Bar. – RockPaperLizard – 2015-06-30T23:55:39.833

You can also use Fiddler to check where the suggestion came from, assuming it came through http, otherwise, maybe wireshark to dig through all raw traffics.

– Chris.C – 2015-07-01T00:55:53.817