Re: [systemd-devel] systemd-resolved auto configure DNS server changed?
On 20/02/2021 21:23, Lennart Poettering wrote: Which software manages that interface? systemd-networkd? NetworkManager? Something else? Figure out which software actually listens to those RA messages and then propagates it to resolved. And then figure out why it does that, i.e. whether it was configured that way. OK. NetworkManager is responsible for the interface. Turned out to be a NetworkManager setting. Thanks for your help. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-resolved auto configure DNS server changed?
On Sa, 20.02.21 07:02, Ed Greshko (ed.gres...@greshko.com) wrote: > > > Link 2 (enp1s0) > > > Current Scopes: LLMNR/IPv4 LLMNR/IPv6 > > > Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS > > > DNSSEC=no/unsupported > > > > > > So, now my question, why wasn't the dnsmasq server found/configured as > > > had been the case? > > > An intentional change or unintentional change? > > I am not sure which software manages that interface, but it would be > > worth figuring that out, and then checking whether it propagated that > > DNS info to resolved. > > > > Well, I determined that in both the systemd-246.6-3 and systemd-246.10-1 > cases (the only changes made) > the same Router Solicitation and Router Advertisement occur. > > So, the only conclusion that I can come to is that something changed between > the two versions of > systemd which results in the Recursive DNS Server option being ignored. > > Would you consider this a candidate for a bug report against systemd? Which software manages that interface? systemd-networkd? NetworkManager? Something else? Figure out which software actually listens to those RA messages and then propagates it to resolved. And then figure out why it does that, i.e. whether it was configured that way. Lennart -- Lennart Poettering, Berlin ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-resolved auto configure DNS server changed?
On 20/02/2021 00:30, Lennart Poettering wrote: The fallback servers are only used as last resort, if there's nothing else known. They are *fallback* as the name says. Most likely the DNS servers were acquire by your network management solution (NetworkManager or networkd) and set on the device. Maybe theym come from IPv6 RA? OK. I have found that, using wireshark, there is a Type: Router Solicitation (133) followed by Type: Router Advertisement (134) which contains ICMPv6 Option (Recursive DNS Server fe80::5054:ff:fe9a:e849) Then, continuing my research I upgraded systemd to systemd-246.10-1.fc33. In that version there are no FallbackDNS servers defined by default. Yeah, i think that's a bad change. I am not sure where the benefit of having a non-working system is... Scratching my head on that one as well. Link 2 (enp1s0) Current Scopes: LLMNR/IPv4 LLMNR/IPv6 Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported So, now my question, why wasn't the dnsmasq server found/configured as had been the case? An intentional change or unintentional change? I am not sure which software manages that interface, but it would be worth figuring that out, and then checking whether it propagated that DNS info to resolved. Well, I determined that in both the systemd-246.6-3 and systemd-246.10-1 cases (the only changes made) the same Router Solicitation and Router Advertisement occur. So, the only conclusion that I can come to is that something changed between the two versions of systemd which results in the Recursive DNS Server option being ignored. Would you consider this a candidate for a bug report against systemd? ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-resolved auto configure DNS server changed?
On Fr, 19.02.21 16:29, Ed Greshko (ed.gres...@greshko.com) wrote: > Link 2 (enp1s0) > Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6 > DefaultRoute setting: yes > LLMNR setting: yes > MulticastDNS setting: no > DNSOverTLS setting: no > DNSSEC setting: no > DNSSEC supported: no > Current DNS Server: fe80::5054:ff:fe9a:e849%32767 > DNS Servers: fe80::5054:ff:fe9a:e849%22096 > DNS Domain: ~. > > The IPv6 address of fe80::5054:ff:fe9a:e849 is that of the Virtual Bridge and > wireshark does confirm > DNS requests are being sent to that address' port 53 where dnsmasq is running. > > I have no idea how systemd-resolved discovered this server? Why wasn't a > Fallback Server > selected used? The fallback servers are only used as last resort, if there's nothing else known. They are *fallback* as the name says. Most likely the DNS servers were acquire by your network management solution (NetworkManager or networkd) and set on the device. Maybe theym come from IPv6 RA? > Then, continuing my research I upgraded systemd to systemd-246.10-1.fc33. In > that version > there are no FallbackDNS servers defined by default. Yeah, i think that's a bad change. I am not sure where the benefit of having a non-working system is... > Link 2 (enp1s0) > Current Scopes: LLMNR/IPv4 LLMNR/IPv6 > Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported > > So, now my question, why wasn't the dnsmasq server found/configured as had > been the case? > An intentional change or unintentional change? I am not sure which software manages that interface, but it would be worth figuring that out, and then checking whether it propagated that DNS info to resolved. Lennart -- Lennart Poettering, Berlin ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] systemd-resolved auto configure DNS server changed?
First a little background. I'm using a Fedora 33 system in a qemu VM. I was doing some research on a question which arose on a Fedora mailing list regarding changes to FallbackDNS. I don't know if this change was universal or Fedora only. But a recent update changed the default to have no FallbackDNS servers defined. In doing my research I used the default install of Fedora 33 which is running systemd-246.6-3.fc33. I did not supply a DNS server in the static IP settings and I purposely created a broken /etc/systemd/resolved.conf file with the bad entry of DNS=192.168.1.142,192.168.1.1 DNS resolution works and I fully expected that one of the defined FallbackDNS servers would be used. However, resolvectl shows Global LLMNR setting: resolve MulticastDNS setting: no DNSOverTLS setting: no DNSSEC setting: no DNSSEC supported: no Fallback DNS Servers: 1.1.1.1 8.8.8.8 1.0.0.1 8.8.4.4 2606:4700:4700:: 2001:4860:4860:: 2606:4700:4700::1001 2001:4860:4860::8844 DNS Domain: greshko.com Link 2 (enp1s0) Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6 DefaultRoute setting: yes LLMNR setting: yes MulticastDNS setting: no DNSOverTLS setting: no DNSSEC setting: no DNSSEC supported: no Current DNS Server: fe80::5054:ff:fe9a:e849%32767 DNS Servers: fe80::5054:ff:fe9a:e849%22096 DNS Domain: ~. The IPv6 address of fe80::5054:ff:fe9a:e849 is that of the Virtual Bridge and wireshark does confirm DNS requests are being sent to that address' port 53 where dnsmasq is running. I have no idea how systemd-resolved discovered this server? Why wasn't a Fallback Server selected used? Then, continuing my research I upgraded systemd to systemd-246.10-1.fc33. In that version there are no FallbackDNS servers defined by default. Owing to previous behavior I was expecting DNS resolution to still work. (Not that I really wanted it to) But it didn't. [egreshko@f33T ~]$ host cnn.com Host cnn.com not found: 2(SERVFAIL) and [egreshko@f33T ~]$ resolvectl Global Protocols: LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported resolv.conf mode: stub DNS Domain: greshko.com Link 2 (enp1s0) Current Scopes: LLMNR/IPv4 LLMNR/IPv6 Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported So, now my question, why wasn't the dnsmasq server found/configured as had been the case? An intentional change or unintentional change? ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
