Questions tagged [systemd-resolved]

Systemd Network Name Resolution manager

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57
votes
3answers
104k views

How to configure systemd-resolved and systemd-networkd to use local DNS server for resolving local domains and remote DNS server for remote domains?

I'm connected to local area network with access to the Internet through gateway. There is DNS server in local network which is capable of resolving hostnames of computers from local network. I would ...
14
votes
5answers
55k views

Why doesn't systemd-resolved use my local DNS server?

I'm using a local BIND9 server to host some local dns records. When trying to dig for a local domain name I can't find it if I don't explicitly tell dig to use my local BIND9 server. user@heimdal:~$ ...
14
votes
1answer
19k views

Override Ubuntu 20.04 DNS using systemd-resolved

How do I configure an Ubuntu 20.04 system so it overrides the default DNS? It seems that by default there is a global and per-link DNS setting. I tried a couple of things that did not work: Edit /...
13
votes
2answers
8k views

How to allow systemd-resolved to listen to an interface other than loopback?

systemd-resolved is a daemon that, among other things, acts as a DNS server by listening IP address 127.0.0.53 on the local loopback interface. I would like to let the daemon listen to another ...
12
votes
1answer
3k views

What's the difference between /run/systemd/resolve/stub-resolv.conf and /run/systemd/resolve/resolv.conf?

For configuring custom DNS servers in a brand new Kubuntu 19.10 laptop it wasn't enough with adding to /etc/systemd/resolved.conf: DNS=77.88.8.7 77.88.8.3 #Yandex's DNS with no porn even on Google ...
11
votes
5answers
16k views

How to configure systemd-resolved for mdns multicast dns on local network?

Ubuntu 18 I've done a ton of research and am close to pulling this picture together but can't quite understand: How can I configure systemd-resolved for mdns? My goal specifically: to bring up a ...
10
votes
2answers
3k views

What is the recommended way to set a global DNS server override on a system using systemd-resolved?

I would like my newer GNU/Linux system (Ubuntu 18.04 LTS) to use a single, manually-configured, DNS server for all DNS queries. In the past, I could simply do echo "nameserver 1.1.1.1" | sudo tee /etc/...
9
votes
2answers
9k views

What are DNS server, resolver and stub resolver?

https://www.freedesktop.org/software/systemd/man/systemd-resolved.service.html#Description says Additionally, systemd-resolved provides a local DNS stub listener on IP address 127.0.0.53 on the ...
7
votes
2answers
10k views

How to make systemd-resolved stop trying to use offline DNS servers?

I have configured my DHCP server to supply two nameservers for redundancy, so that if one is offline the other one can be used. I have configured my PCs with systemd-resolved and according to ...
7
votes
3answers
6k views

How do you remove bad DNS server IPs from systemd-resolved?

So I was testing a router and it added some random IPv6 addresses to all the machines on my network, including my DNS server. Somehow those IPs were broadcasted around as valid DNS servers (not sure ...
6
votes
2answers
2k views

How single-label dns lookup requests are handled by systemd-resolved?

I looked into the systemd-networkd and systemd-resolved: systemd.network(5) on manpages.ubuntu.com systemd-resolved.service(8) on manpages.ubuntu.com and I am confused by some words: systemd-...
6
votes
2answers
2k views

systemd-resolved block a domain name

Using systemd-resolved how do I block, route, or resolve, a domain name to a black hole, or a nowhere address. Bonus points for subdomains as well. I tried a single domain in /etc/hosts: 127.0.0.1 ...
5
votes
1answer
6k views

Clarifying four modes of handling /etc/resolv.conf in systemd-resolved

I have read about systemd-resolved.service https://www.freedesktop.org/software/systemd/man/systemd-resolved.service.html and learnt four modes of handling /etc/resolv.conf. /run/systemd/resolve/stub-...
5
votes
1answer
455 views

Going all-in on DNSSEC

I have been doing an effort to go full on DNSSEC on my system with the following setup: dnscrypt-proxy installed, up and running on 127.0.0.1 with require_dnssec = true systemd-resolved running, with ...
5
votes
0answers
1k views

Why is systemd-resolved falling back to using Google Public DNS over IPv6 when I did not configure it to do that?

I'm having problems with SystemD's resolved service on Ubuntu 18.10 - on my wireless network we have an IPv6 subnet that is tunneled through some weird network setup (work stuff) and can't be used for ...
4
votes
1answer
3k views

What is the difference between resolvconf, systemd-resolve, and avahi?

I'm currently working on a project that has required some DNS troubleshooting, however I am fairly new to the wonderful world of networking and am at a bit of a loss as to where to begin. My specific ...
3
votes
1answer
511 views

systemd version 219 from CentOS 7 listening on random UDP port

Why does systemd-resolved from systemd version 219 listen on one random UDP port? One of my machines listens on port 58557 (CentOS 7 with systemd version 219). sudo netstat -tunlp|grep -P '^Active|^...
3
votes
0answers
2k views

How to set systemd-resolve DNS servers?

Ubuntu 18.04 is not respecting local configuration anymore. Since I cannot have my DHCP server advertising anymore the DNS servers, I want to set up the clients manually (LXD containers). I tried to ...
2
votes
4answers
3k views

dnsmasq & systemd Causing Intermittent CPU Spikes

Problem: Running Ubuntu 17.10 I have been trying to resolv (hehe) this issue for about a week now and despite countless Google searches and about 20 different attempts, I can not stop dnsmasq from ...
2
votes
1answer
178 views

DNS: a “short” query (UDP) does not return an address, but a “long” (ANY, TCP) query does

This is a companion to an AskUbuntu question I posted before I had learned enough to ask this question. (This is for Ubuntu 18.04) By watching the debug output from systemd-resolved, I can do ...
2
votes
2answers
2k views

How to correctly disable systemd-resolved on port 53 for avoiding clash with dnsmasq in Ubuntu 20.04…?

I'm trying to use dnsmasq on Ubuntu 20.04 and I get a port clash on port 53 with systemd-resolved. So I've found a few suggestions on solutions, but they seem to be dated or not applicable to my case. ...
2
votes
1answer
1k views

Where's my stub-resolve.conf missing?

I'd like to start using systemd-resolved on Oracle Linux 7.6. I've installed systemd-networkd and systemd-resolved. I've enabled these services and I've disabled network and NetworkManager. From the ...
2
votes
1answer
3k views

What are link “scopes” in systemd-resolved?

While trying to fix a DNS issue with NetworkManager's ModemManager on Ubuntu, I came across this difference in the output of systemd-resolve --status when connected. (ping ip works, manually editing /...
2
votes
0answers
26 views

How to configure systemd-resolved to use chosen DNS servers on public wifi

When I'm at home or at work I'd like my laptop to accept the DNS servers offered by the DHCP server but when I'm on a public wireless server at a cafe or coffee place, I'd prefer to use DNS servers I ...
2
votes
0answers
221 views

Why is resolvectl missing from CentOS 7

I've got a Linux system (Centos 7) on a LAN with about 70 Windows machines, but the Windows machine names are not in the DNS. I'm trying to use LLMNR (Link-Local Multicast Name Resolution) to resolve ...
2
votes
0answers
76 views

systemd-resolved's ResolveUnicastSingleLabel setting does not seem to work with non-search domains

ResolveUnicastSingleLabel=yes still does not seem to solve the problem of non-fully-qualified domain names (NFQDN) not being resolved. I use a single wireguard tunnel to my corporate network (with ...
2
votes
1answer
889 views

Remove a DNS server from systemd-resolved?

I have connected to an openconnect VPN like thing, and it has added a DNS server (& DNS domain) to my systemd-resolved, and they don't work, so using the internet is slowed down, because every new ...
2
votes
1answer
293 views

How to properly enable DNSoverTLS on Systemd

I came across this strange problem the other day. I enabled DNS over TLS(DoT) months ago on my laptop. My laptop had been sitting at home until I decided to take it with me to town. Recently I ...
2
votes
0answers
89 views

How do I (correctly) manage/update search domains with systemd?

I have a system (running Ubuntu 20.04) with multiple network interfaces and I realized that the search domains (I'm looking at /etc/resolv.conf, which I know is just a symlink to a systemd-resolved ...
2
votes
0answers
174 views

systemd-resolved browse for mdns services

Can systemd-resolved be used to browse for mdns services the same way like avahi-browse? For example: $ avahi-browse _smb._tcp + eno1 IPv6 PC1 Microsoft Windows ...
2
votes
0answers
219 views

per-link (VPN) systemd-resolved configuration but keep link unmanaged by systemd-networkd

Background I manage my WLAN interface through systemd-networkd and use systemd-resolved for the whole system. I have several VPN connections managed by OpenVPN or Openconnect. I have them properly ...
2
votes
1answer
342 views

Prevent NetworkManager from setting ~. search domain per-link on systemd-resolved

I'm trying to use the DNS over at /etc/systemd/resolved.conf in their capacity as DNS over TLS providers, but NetworkManager somehow manages to set ~. as search domain on the connections it sets up. ...
2
votes
0answers
528 views

On Ubuntu 18.04 what is the way to remove dnsmasq and systemd-resolved and switch to resolv.conf

I noticed that with introduction with the combo of systemd-resolved and dnsmasq in Ubuntu 18.04 network connectity is becoming a luxury feature. What is the correct way to remove these components in ...
2
votes
1answer
336 views

do “search domain” in networkd configuration and LLMNR conflict?

in networkd man page, the search domains are used to handle single-label names: The domains without the prefix are called "search domains" and are first used as search suffixes for extending single-...
2
votes
1answer
64 views

host command takes a long time on .local queries

I'm using systemd-resolved configured for mDNS. host command takes a long time on .local queries. Example: $ time host blah.local ;; connection timed out; no servers could be reached real 0m10....
1
vote
1answer
5k views

Arch Linux resolving issues

I have a Rasberry Pi running Arch and i'm encountering some weird resolving behavior. Long story short, dig and nslookup can resolve hostnames, curl, wget, pacman can't. If i add a host in /etc/hosts ...
1
vote
1answer
2k views

Default DNS server settings

I recently updated my Ubuntu which ended in a shot DNS config. I am able to add a nameserver to /etc/resolvconf/resolv.conf.d/tail (and restart the service) to get DNS resolution for everything ...
1
vote
1answer
3k views

DNS is not applied with systemd-resolved [closed]

I'm using Kubuntu 18.04. When I'm in the office network, everything works fine, but when I connect to any other network (wired of wifi) I don't get proper DNS names - the old ones are still in systemd-...
1
vote
1answer
619 views

Why does systemd-networkd consider UseDomains= (domain search list from DHCP) less safe than LLMNR?

UseDomains= Takes a boolean argument, or the special value "route". When true, the domain name received from the DHCP server will be used as DNS search domain over this link, similar to the ...
1
vote
1answer
18 views

APT - temporary failure in name resolution error

I have a really annoying & confusing issue about domain name resolution, focused only on apt/apt-get utility. When I try apt update, it gives me (sorry in french) root@myhostname:~# apt update Err ...
1
vote
0answers
89 views

Systemd-resolved service stopping unexpectedly

Almost every day, sometimes more than once a day, Systemd-resolved crashes on my fedora machine. Output: https://pastebin.com/sgN3C0BU (I removed some stuff which I did not know if it was safe to ...
1
vote
0answers
50 views

Tool to manage and set right domain resolution

This horror story began a week ago when after an update, my Arcolinux install started behaving erratically and some sites (at random) won't open (they would after I left them for a while and tried ...
1
vote
1answer
812 views

Setting domains in resolvectl results in timeouts

For some reason I can't manage to set domains for resolvectl. Either I don't understand what it does at all or something is weird for me. Once I set a domain e.g. sudo resolvectl domain enp2s0 example....
1
vote
0answers
776 views

How to disable IPv6 short hostname resolution

For a long time I've been able to SSH to other hosts on my network just with the short name, e.g. ssh otherpc and it recognises it's a short name, adds the DNS search suffix, does a lookup for otherpc....
1
vote
1answer
175 views

Make systemd-resolved ignore a DNS server and only use the one I specify

I am experiencing an issue with DNS and to help narrow down the problem, I have been asked to configure my machine's DNS settings manually, only specifying one DNS server instead of the two returned ...
1
vote
0answers
437 views

systemd-resolved add option rotate Ubuntu 18.04

I'm trying to add options rotate to my resolv.conf on Ubuntu 18.04 LTS upgrade Ubuntu 16.04 LTS: /etc/resolv.conf -> ../run/resolvconf/resolv.conf handled just by adding options rotate to /etc/...
1
vote
0answers
262 views

systemd-resolved - how to stop forwarding and go direct to DNSBLs / RBLs (mailserver blacklists)

My mailserver needs to check IPs of incoming connections against external blacklists, this is done by a DNS lookup but it must go direct to the blacklist and not via the usual configured DNS ...
0
votes
2answers
185 views

How do you block network acceess to systemd?

How would one quarantine any systemd processes from ever using ANY network interface or resources at OS-level? Overview Minimalistically, I'd like to setup a Linux gateway. Simple NAT, forwarding ...
0
votes
1answer
122 views

How to understand and mitigate the Evil DNS remote attack under linux systems?

A new vulnerability has discovered on the systemd package called Evil DNS allowing the remote control of a linux machine. From the security-tracker.debian , the debian Stretch , Buster and Sid are ...
0
votes
1answer
54 views

How to reset DNS to its default after changing it with systemd-resolve?

I'm using Xubuntu 18.04. AFAIK, DNS could be changed with sudo systemd-resolve -i wlp3s0 --set-dns="xxx-yyy-aaa-bbb". Now, how can I revert it back to the default state? Before setting it, ...