No breaking changes in the stable API. Changes to configuration are handled with deprecation warnings where possible, with two exceptions:
- Specifying an network interface using a hostname is no longer possible
- Previously AssumeMulticastCapable configuration accepted more-or-less arbitrary wildcards, now it must be either be "*" or a list of interfaces
Both have always been slightly unusual features that have not really seen much use. Supporting it in the new configuration would only have added unnecessary complexity.