At work we have 2 DNS servers (172…, 8.8.8.8.8). The problem is that we are supposed to use internal DNS for internal address recognition, but for some reason on Fedora 35/36 from time to time on my local ntb it sets 8.8.8.8 and sometimes 172. I haven’t changed anything within the DNS configuration…

Well, if the DNS resolver addresses are being delivered via DHCP, there’s no mechanism to do that. If you are configuring your system locally, then you can certainly configure systemd-resolved to only use the internal resolver for names that are in the internal zone(s).

What method have you used in the past to tell the system which DNS resolver should be used for which names? It can’t guess that information :slight_smile: If you’re saying that only 172.16.53.8 should be used and never 8.8.8.8, then you should remove 8.8.8.8 from the configuration. If your system i…

[image] Kevin P. Fleming: You definitely don’t want to rely on any ordering behavior when there are multiple addresses, that will be unreliable. Traditionally the primary DNS server is always used. The secondary DNS server is not used unless the primary is nto available (is the behavior speci…

[image] Kevin P. Fleming: I’m not aware of any mechanism in DHCP to indicate ‘primary’ or ‘secondary’; there’s just a list of IP addresses in an option in the DHCP response. If the one in the first position is supposed to be considered ‘primary’ that may be common practice, but not actually spec…

That RFC is related to providing authoritative name service for a zone, not for providing recursive resolver service to clients. Very different part of the DNS world :slight_smile: But I do agree, if usage of the internal resolvers is necessary to resolve internal names, only the addresses of the i…

thx for replies, i have no idea how it was in the past, i think that there was only one dns server. the idea behind adding 8.8.8.8 was to secure connection if case of drop out 172.16.53.8. I will try suggest to limit internal dns to resolving internal names only :slight_smile:

[image] Kevin P. Fleming: you can certainly configure systemd-resolved to only use the internal resolver for names that are in the internal zone(s). I’m not a Systemd fan so please forgive my ignorance… Is it possible to configure Systemd to use something like mDNS first for local names, and …

I don’t believe resolved supports mDNS at all.

Yes, it is. systemd-resolved actually implements two similar protocols. LLMNR is enabled by default and is compatible with multicast protocol used also on Windows. It allows only resolution, but does not serve the name otherwise. mDNS (Apple compatible) IS supported by systemd-resolved, but is not e…

It should be possible to create entry for just selected subdomains to target local server, but default root domain might then be served by multiple of equal servers. I am not sure if this can be configured in systemd-resolved in simple way. I will provide example for dnsmasq then, where I am sure o…

Current DNS server systemd-resolved

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noloader (Jeffrey Walton) May 18, 2022, 5:58pm 3

Traditionally the primary DNS server is always used. The secondary DNS server is not used unless the primary is nto available (is the behavior specified by a RFC?)

But there’s no telling what Systemd does. Poettering makes some shit up as he goes.

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Current DNS server systemd-resolved

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