When -ipv6 is in use: 

o	ipv6_registration_ok.test: IPv6 requests to CB work
o	ipv6_registration_with_ipv4.test: IPv4 requests to CB work
o	ipv6_subscription_sequence_onchange.test: notifications sent to IPv6 addresses work (e.g. using ::1 in <reference>)
o	ipv6_subscription_sequence_onchange_with_ipv4.test: notifications sent to IPv4 addresses work

When not using -ipv6: 

o	ipv6_registration_fails.test : IPv6 request to CB doesn't work
o	notifications sent to IPv6 addresses doesn't work
        (In this case even if –ipv6 is not set … if subscription are made with an IPv6, notification is tried to send with IPv6 mode )