DNS

• DNS y funcionamiento
• dnsmasq
• bind9
• 127.0.0.1 VS 127.0.1.1
• https://www.dns0.eu/
• https://one.one.one.one/

• esbrinar qui gestiona les dades de xarxa (netplan)
• aplicar els canvis (networkmanager en desktops)

• Cloudflare DNS (1.1.1.1, 1.0.0.1)
• OpenDNS (208.67.222.222, 208.67.220.220)
• Google Public DNS (8.8.8.8, 8.8.4.4)

• interficie de xarxa:

  ip a
  ifconfig -a

Search domain means the domain that will be automatically appended when you only use the hostname for a particular host or computer. This is basically used in a local network.

/etc/network/interfaces

dns-search xyz.com ##If you put this into /etc/network/interfaces<code>
<code properties>search xyz.com ##If you put this into /etc/resolvconf/resolv.conf.d/base|head|tail

host test
test.xyz.com has address 192.168.1.5

nslookup test
Server:     192.168.1.11
Address:    192.168.1.11#53
 
Name:   test.xyz.com
Address: 192.168.1.5

/via: https://askubuntu.com/questions/584054/how-do-i-configure-the-search-domain-correctly

• /etc/resolv.conf es symlink de fichero generado dinámicamente
• /etc/resolvconf/resolv.conf.d/head añade al principio de /etc/resolv.conf
• se gestiona a través de systemd-resolved → /etc/systemd/resolved.conf

• /etc/systemctl/resolved.conf
• /etc/resolv.conf
  • no recomanat, sobreescrit per NetworkManager

  • nameserver 8.8.8.8
    nameserver 8.8.4.4

• /etc/hosts:

  78.47.249.138 wiki.fidmag.org

• resolvectl status

• llistat DNS:

  resolvectl --list

• actualitzar canvis pendents:

  resolvectl --enable-updates

• interficie responent:

  resolvectl -i

• update files:

  resolvectl -u

• identificar el netplan fet servir:

  cat /etc/netplan/01-network-manager-all.yaml

• NetworkManager

  # Let NetworkManager manage all devices on this system
  network:
    version: 2
    renderer: NetworkManager 

• DHCP

  network:
    version: 2
    ethernets:
      eth0:
        dhcp4: true
        nameservers:
          addresses: [8.8.8.8, 8.8.4.4]

• IP-fija

  network:
    version: 2
    ethernets:
      eth0:
        dhcp4: false
        addresses: [192.168.1.10/24]
        gateway4: 192.168.1.1
        nameservers:
          addresses:[208.67.222.222, 208.67.220.220]

• aplicar:

  sudo netplan apply
  sudo netplan generate # si problemas y repetir apply

• Interfície gràfica
• després d'aplicar canvis, reiniciar o:

  sudo systemctl restart NetworkManager

• nmcli

• nmcli connection show

• nmcli device show eno1

• NO:

  systemctl status systemd-resolved.service

• clear DNS debian:

  sudo systemd-resolve --flush-caches

• full config?:

  systemd-analyze cat-config systemd/resolved.conf