1284446 - Firefox is doing DNS lookup when I specify HTTP address with IP number

Status: RESOLVED INVALID

(Core :: Networking: HTTP, defect)

Description

[Pascal Byrne]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:47.0) Gecko/20100101 Firefox/47.0
Build ID: 20160604131506

Steps to reproduce:

When I enter a URL using the private IP address for my local machine (http://192.168.50.41), Firefox tries to do DNS lookup for the address. This is adding a huge overhead to the page load. 

I am using a statically assigned IP address and DNS server. I am using the Google DNS servers: 8.8.8.8 and 4.4.4.4



Actual results:

The message 'Looking up 192.168.50.1' is displayed in the message bar accompanied by a long wait 



Expected results:

No DNS lookup.

Comment 1

[Pascal Byrne]

Page reload in Chrome: 1 second
Page reload in Firefox: 11 seconds

Comment 2

[Patrick McManus [:mcmanus]]

I'm not convinced the problem is trying to resolve a dotted decimal.. that might just be the last thing sent to the status bar.

Can you please reproduce your test case with logging enabled and add that log to this bug?

https://developer.mozilla.org/en-US/docs/Mozilla/Debugging/HTTP_logging

Comment 3

[Pascal Byrne]

Includes both the initial load of the page and then a reload

Comment 4

[Pascal Byrne]

Attachment: log.zip

Comment 5

[Pascal Byrne]

After a little investigation, I find that it is security addons that are causing the slowdown. Apologies.