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sse450 avatar Ubuntu

Ubuntu 20.04 server slow DNS

vn flag
sse450

I have an VPS running Ubuntu 20.04. Lately, noticed that DNS lookups are slow.

Here is several config files:

/etc/resolv.conf

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.

nameserver 10.10.1.1
nameserver 127.0.0.53
search invalid

Interesting entry "10.10.1.1" which is my LAN gateway. But it has nothing to do with a remote VPS.

/etc/netplan/01-netcfg.yaml

network:
  version: 2
  renderer: networkd
  ethernets:
    eth0:
      match:
        macaddress: 00:50:56:41:ac:23
      addresses:
        - 164.68.xxx.xxx/32
        #- 2a02:c207:xxxx:xxxx:0000:0000:0000:0001/64
      #gateway6: fe80::1 
      routes:
        - to: 0.0.0.0/0
          via: 164.68.115.1
          on-link: true
      nameservers:
        search: [ invalid ]
        addresses:
          - 8.8.8.8
          - 1.1.1.1
          #- 2a02:c207::1:53
          #- 2a02:c207::2:53

systemd-resolve --status

Global
       LLMNR setting: no                  
MulticastDNS setting: no                  
  DNSOverTLS setting: no                  
      DNSSEC setting: no                  
    DNSSEC supported: no                  
  Current DNS Server: 10.10.1.1           
         DNS Servers: 10.10.1.1           
          DNS Domain: invalid             
          DNSSEC NTA: 10.in-addr.arpa     
                      16.172.in-addr.arpa 
                      168.192.in-addr.arpa
                      17.172.in-addr.arpa 
                      18.172.in-addr.arpa 
                      19.172.in-addr.arpa 
                      20.172.in-addr.arpa 
                      21.172.in-addr.arpa 
                      22.172.in-addr.arpa 
                      23.172.in-addr.arpa 
                      24.172.in-addr.arpa 
                      25.172.in-addr.arpa 
                      26.172.in-addr.arpa 
                      27.172.in-addr.arpa 
                      28.172.in-addr.arpa 
                      29.172.in-addr.arpa 
                      30.172.in-addr.arpa 
                      31.172.in-addr.arpa 
                      corp                
                      d.f.ip6.arpa        
                      home                
                      internal            
                      intranet            
                      lan                 
                      local               
                      private             
                      test                

Link 1023 (veth9d95ab2)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1021 (veth99920db)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1019 (veth5cafc68)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 973 (br-mailcow)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1053 (veth09324c2)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1051 (vethf1d408c)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1049 (vethe60b315)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1047 (vetha316427)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1045 (vethbad6c4e)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1043 (vethf514b82)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1039 (vethbf845fa)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1037 (vethd4a1138)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1035 (veth9eb732c)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1033 (veth43c33c6)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1031 (veth2862530)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1029 (vethab58e63)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 4 (docker0)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 3 (agora)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 1027 (veth1d4fe9f)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  

Link 2 (eth0)
      Current Scopes: DNS    
DefaultRoute setting: yes    
       LLMNR setting: yes    
MulticastDNS setting: no     
  DNSOverTLS setting: no     
      DNSSEC setting: no     
    DNSSEC supported: no     
         DNS Servers: 8.8.8.8
                      1.1.1.1
          DNS Domain: invalid

Link 1025 (veth2c630a2)
      Current Scopes: none
DefaultRoute setting: no  
       LLMNR setting: yes 
MulticastDNS setting: no  
  DNSOverTLS setting: no  
      DNSSEC setting: no  
    DNSSEC supported: no  
lines 173-228/228 (END)

There is no "10.10.1.1" in /etc/netplan/01-netcfg.yaml. But "netplan apply" still introduces 10.10.1.1.

I would appreciate any help.

Thank you.

Edit:

ls -al /etc/resolv.conf
lrwxrwxrwx 1 root root 29 Apr 13  2022 /etc/resolv.conf -> ../run/resolvconf/resolv.conf

By the way, I deleted 10.10.1.1 from /etc/resolv.conf and run "netplan apply". 10.10.1.1 came back again. I don't know where it is coming from.

134
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dns
chili555 avatar
cn flag
chili555
Please edit your question to show the result of the terminal command: `ls -al /etc/resolv.conf` Welcome to Ask Ubuntu.
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Score:4
chili555 avatar Ubuntu
cn flag
chili555

Your `/etc/resolv.conf symbolic link is incorrect. Please do:

sudo rm -f /etc/resolv.conf
ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf

Reboot and test.

+ 2
sse450 avatar
vn flag
sse450
Perfect! Thank you chili555. By the way, how come this happened? Never messed with the conf files.
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chili555 avatar
cn flag
chili555
I haven't any idea why this happens. I have worked on several variations of this issue in the past few years. If my answer has been helpful, please accept it: https://askubuntu.com/tour The searchers will appreciate it.
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