Merge pull request #6681 from mpg/changelog-6264
Add ChangeLog entry for DTLS Connection ID
diff --git a/ChangeLog.d/dtls-connection-id.txt b/ChangeLog.d/dtls-connection-id.txt
new file mode 100644
index 0000000..eb9e216
--- /dev/null
+++ b/ChangeLog.d/dtls-connection-id.txt
@@ -0,0 +1,16 @@
+Features
+ * Add support for DTLS Connection ID as defined by RFC 9146, controlled by
+ MBEDTLS_SSL_DTLS_CONNECTION_ID (enabled by default) and configured with
+ mbedtls_ssl_set_cid().
+
+Changes
+ * Previously the macro MBEDTLS_SSL_DTLS_CONNECTION_ID implemented version 05
+ of the draft, and was marked experimental and disabled by default. It is
+ now no longer experimental, and implements the final version from RFC 9146,
+ which is not interoperable with the draft-05 version. If you need to
+ communicate with peers that use earlier versions of Mbed TLS, you
+ need to define MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT to 1, but then you
+ won't be able to communicate with peers that use the standard (non-draft)
+ version. If you need to interoperate with both classes of peers with the
+ same build of Mbed TLS, please let us know about your situation on the
+ mailing list or GitHub.
