Keycloak 11 H2database listening on 0.0.0.0 by default

After installation of keycloak 11.0.0 by following the instructions on medium.com/@hasnat.saeed/setup-keycloak-server-on-ubuntu-18-04-ed8c7c79a2d9

I did a netstat -tulpn … and saw four different ports being listened to by the keycloak process.

johan@instance-12:~$ sudo netstat -tulpn 32999
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:8443 0.0.0.0:* LISTEN 232085/java
tcp 0 0 127.0.0.1:9990 0.0.0.0:* LISTEN 232085/java
tcp 0 0 0.0.0.0:32999 0.0.0.0:* LISTEN 232085/java
tcp 0 0 0.0.0.0:8080 0.0.0.0:* LISTEN 232085/java

I am curious about the listener on port 32999 and why it has to listen on 0.0.0.0 by default. I tried it on different box and saw that the listener port changed but the service itself is still there.

johan@instance-12:~$ nc localhost 32999
[type random stuff]
90047BVersion mismatch, driver version is “0” but server version is “17”???_??org.h2.jdbc.JdbcSQLException: Version mismatch, driver version is “0” but server version is “17” [90047-197]
at com.h2database.h2@1.4.197//org.h2.message.DbException.getJdbcSQLException(DbException.java:357)
at com.h2database.h2@1.4.197//org.h2.message.DbException.get(DbException.java:179)
at com.h2database.h2@1.4.197//org.h2.server.TcpServerThread.run(TcpServerThread.java:97)
at java.base/java.lang.Thread.run(Thread.java:834)

Any ideas?

Thanks,
Johan