If an IPv6 address is unreachable, but you can reach the IPv4 one, you can set the preference to IPv4 for that particular address by adding a line such as this in /etc/gai.conf:
1 |
precedence ::ffff:198.145.11.105/128 100 |
That will set the preference for host 198.145.11.105 to IPv4.
See gai.conf(5) for details.