ipconfig /flushdns run over 24 hours

[StefanStrauss83]

Hello,
Sorry, for my bad english.

I Use the Update Batch.
ipconfig /flushdns run more than 24 hours with many CPU usage. In this Time the PC is offline.
He build the local DNS Database in this Time?
The PC has a SSD and 2,5GHz Processor und 8GB RAM.
Whats the problem?

[mitchellkrogza]

Windows seems to really struggle with a very large hosts file. I'm really not sure why flushdns is hanging for so long though. Have you tried running update straight after reboot and not after the machine has been running for a long time?

[StefanStrauss83]

After each restart, the laptop was offline for 1 hour and the DNS client service had CPU load. I have emptied the hosts again.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[spirillen]

Hey @StefanStrauss83 you should take a look at the unbound for windows.... That is the right tool to manage this, hosts files are so 90's and for some weird reasons still a live.

You can find unbound at https://nlnetlabs.nl/projects/unbound/download/ and I have a small quick start config here https://www.mypdns.org/w/rpzunbound/ and here https://gitlab.com/my-privacy-dns/rpz-dns-firewall-tools/unbound and here https://gitlab.com/rpz-zones/toolbox/-/tree/master/unbound. Chose should be able to get you started, not to use hosts files as sources but partial RPZ. (Response Policy Zones are still not fully supported in unbound) but I have a lot of converted hosts files to RPZ here https://gitlab.com/my-privacy-dns/rpz-dns-firewall-tools/unbound/-/tree/master/nxdomain

Tell us what you think after trying it.

PS: Here is a short and dirty speed comparisons between hosts files vs a real recursor https://www.mypdns.org/w/performance_test_of_hosts_file_vs_dns-recursors/

NLnet Labs

Unbound - Download

⚡ Unbound

GitLab

Projects · My Privacy DNS Firewall / RPZ DNS firewall tools / Unbound

The zone files to be used with [Unbound](https://nlnetlabs.nl/projects/unbound/about/) From NLNetLabs

GitLab

unbound · master · RPZ Zones / toolbox

The toolbox is for various collections of scripts to help improve and complete the mission

GitLab

nxdomain · master · My Privacy DNS Firewall / RPZ DNS firewall tools / Unbound

The zone files to be used with [Unbound](https://nlnetlabs.nl/projects/unbound/about/) From NLNetLabs

⚡ Performance Test of Hosts File vs. Dns-recursors

[georgengelmann]

Hello

I tried using the .bat file on Windows 10 - then DNS client CPU usage jumped to 10-20%, network was blocked

I rebooted in safe-mode - copy the hosts.original to hosts (I could not change the hosts file in normal boot mode, because the DNS client was using it and it's not possible to stop the DNS client in normal mode)

The line-breaks are not Windows line-breaks, but that's not the issue here (I tried changing them): Windows can't handle large hosts files. Some added hosts are fine: SpyBot immunization adds 500kB - 10MB is too big for DNS

You should probably remove the Windows .bat file or add a warning.

[spirillen]

Hey @georgengelmann In case you just won't try to install the better, faster and safer approach of installing a DNS recursor like the unbound for windows, I would recommend you to have a look it @ScriptTiger's script ScriptTiger/Unified-Hosts-AutoUpdate#23

For your note about the size of this hostfile will brake most microsoft product, I agree with you.

@funilrys could you point me to a good line in the README.md where to put a note on this, and I will try to find the time for it while my bad disk is restoring 😒

[funilrys]

Please prefer our DNS Server (#590).

Closing.