systemd-resolved
- is part of Ubuntu core and not Bind
- is for apps and the command line to make DNS requests and uses
/etc/resolve.conf for legacy apps.
- is only bound on the loopback adapter at port 53 (i.e. 127.0.0.53:53, 127.0.0.1:53 etc…)
bind receives and responds to DNS requests on specified network interfaces.- 127.0.0.53 is only needed in your network card for the following reasons:
- you have got DNS servers specified in
/etc/systemd/resolved.conf
- you require SplitDNS
- you want to use the benefits of the
systemd-resolved DNS cache
- if 127.0.0.53 is specified in the network card I assume
systemd-resolved ignores this to prevent an infinite loop
- 127.0.0.53 is specified in my network card by default by Ubuntu when I set the server up.