Which is faster: 0.0.0.0 or 127.0.0.1?

When I was experimenting with hosts and Pi-Hole, I read that "0.0.0.0" address in the hosts works faster thфn "127.0.0.1". And now I decided to test and verify it.

About tests

• To automate tests I prepared code on Python "DNS_Loopback_Speed".
• To get more accurate results I performed 10000 tests for each address and took the average.
• I have two devices running Windows 10 and Ubuntu 22.04, so I also compare speed of resolving between Windows and Linux.
• I've seen option of using 127.0.0.0 in hosts, therefore I add it too.
• Just to compare delays between local resolution (hosts) and external DNS servers I add 2 tests (my local Pi-Hole DNS and Google DNS). My devices connected to network via Wi-Fi, so results may not be reliable.

Brief information regarding these IP addresses:

• 0.0.0.0 - non-routable meta-address
• 127.0.0.1 - loopback Internet protocol address = localhost
• 127.0.0.0 - loopback network address

My own secure DNS server - Pi-hole on NanoPi NEO3

I care about my own information security and I don't want to put up with such flow of ads.

The first and the simplest step of the fight is AdBlock plugin in the browser.

Ths second step is custom hosts file. In this manner you may protect a few PCs, but it is difficult to cover each device in your network. Also, large hosts file can affect performance.

The third step is your own DNS server that will filter all requests from each device. The solution is Pi-hole.

As a platform for the Pi-hole I choosed a small device NanoPi NEO3 with 4 ARM cores (Cortex-A53 up to 1.3GHz) and 1 GB RAM (DDR4) on Ubuntu Core 18.

Windows 10: DNS Client load CPU in case of big hosts file

After installing Fall Creators Update (KB4058043, KB4057247, KB4055237, KB4055994) on Windows 10 Pro 1709 (16299.125) I noticed a long delay in the opening of websites.

Symptoms

• The DNS Client service load is about 25% CPU.
• You can't open any website and get access to the internet at all for several minutes.