How to prevent SSHD to listen on an address family
It is possible to control on which address family sshd will listen to. In /etc/ssh/sshd_config, simply add
AddressFamily any
to listen to IPv4 and IPv6 addresses. This is the default. Alternatively, add one of these to listen only to IPv4 (inet) or IPv6 (inet6) respectively.
AddressFamily inet
AddressFamily inet6