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I found this simple tip about how to list DNS entries or visited websites in Windows by typing in the command line:

 ipconfig /displaydns > dnslist.txt

My question is the visited websites in privacy mode of browser will be listed if I retype the same command or the browser will delete them automatically?

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Wael Boutglay
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TL;DR: Yes, it (probably) will.

This is not a function of the web browser, it is a function of the DNS system.

When a computer connects to another computer, it first uses DNS (the domain name system) to look up the ip address. You can think of this as a phonebook. Look up superuser.com in the DNS "phonebook":

C:\> nslookup superuser.com
Server:     10.10.10.10
Address:    10.10.10.10#53

Non-authoritative answer:
Name:   superuser.com
Address: 190.93.247.58
Name:   superuser.com
Address: 190.93.246.58
Name:   superuser.com
Address: 141.101.114.59
Name:   superuser.com
Address: 190.93.244.58
Name:   superuser.com
Address: 190.93.245.58

(this was run on a linux server, then changed slightly. Your results will vary).

This indicates that, to contact superuser.com, you can "dial" any of the "phone numbers" (IP addresses) - the first one listed here is 190.93.247.58.

Because this takes a while (0.2 seconds on my computer!), this information is held locally; often, people will make several connections to the same computer in quick succession (e.g. to download a web page, and several images - this is hugely simplified!). The rules specify how long the information is allowed to be kept, before it has to be looked up again - often 24 hours. The data may be kept in memory or on disk. Restarting your computer should reset this information (though it need not).

Of course, if you want to confirm this, try it - you have everything you need to run this experiment.

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  • long story short, by keeping a list of IPs of recently visited servers, DNS doesnt have to look them up again. – Keltari Aug 31 '15 at 02:17
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    You can also flush the local DNS cache with `ipconfig /flushdns` in Windows, though there usually isn't much point in doing so - and it does nothing about any upstream caching (e.g. at the router or ISP level, depending on how your DNS resolution path is set up). – Bob Aug 31 '15 at 03:49
  • @ Bob One big point for flushing DNS is when Windows caches an address as inaccessible, which can happen if you have Internet connection problems. In this case, even when connection is restored, an address can show up as unresolvable due to cache. In this case, flush will help. – AndrejaKo Aug 31 '15 at 09:42