Status

Current state: Under discussion

...

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

Motivation

Currently with Kafka you cannot have duplicate listeners on the same port. This makes sense when you only have a single IP stack but since we now have both IPv4 and IPv6 there is no reason why you cannot have an IPv4 address and another IPv6 address on the same port.

Public Interfaces

• The proposed changes does not require any changes to public interfaces

Proposed Changes

A tested PR of the proposed changes is available here https://github.com/apache/kafka/pull/11478.

...

Apart from some adding some extra information that gets thrown when the validation in listenerListToEndPoints  fails there are no changes outside of this specific case 

Compatibility, Deprecation, and Migration Plan

• There won't be any impact on current users, the proposal strictly involves adding new behavior and its not possible for current users to run Kafka on this newly proposed behavior since it would fail validation.

Rejected Alternatives

As far as I am aware there aren't any rejected alternatives.