This feature is new in the Solaris Express 11/03 release.
Several new IPv6 functions are started when you select Enable IPv6 during Solaris installation.
The /etc/nsswitch.conf file policies for the hosts database and ipnodes repositories are synchronized so that the same naming repositories are searched for ipnodes and hosts. Now, hosts can resolve any IPv6 addresses that might be in any of the ipnodes repositories.
Destination address selection has been modified to avoid using an IPv6 address for a remote host if no IPv6 routes serve that host. Instead, an IPv4 address is used, to avoid any delays when connecting to remote hosts.
For example, consider the case of an IPv6-enabled host on a network with no IPv6 router. Without the presence of a router, a host has no knowledge of IPv6 routes beyond the local link. Previously, the host experienced timeouts when trying to connect to a preferred IPv6 address. With the new feature for destination address selection, the host prefers an IPv4 destination address. This feature eliminates time-out problems.
For further information, see the System Administration Guide: IP Services.