The various operations for command path `service dns dynamic` can be improved/modernized in a few ways:
- Dynamic DNS client doesn't necessarily has to be attached to an interface. For example, when using `use-web`, the interface isn't used at all.
- There isn't a way of supporting dual-stack configuration because using ipv4 or ipv6 is configured at global level, not per-service level.
- `service` is implicitly tied to `protocol`. One can still setup multiple services per protocol (by choosing a custom service name), but it appears non-obvious.
- The number of protocols (services) supported by ddclient are lot more that supported via VyOS config.
- Currently, op-mode command `show dns dynamic status` isn't compatible with new ddclient version anymore.
NB: While we can continue discussing a possible long term replacement for `ddclient` in T2819, we can still improve the current experience regardless of what we use behind the scene.