on machines with no IPv6 support.
# TYPE DATABASE USER IP-ADDRESS IP-MASK METHOD
-local all all trust
-host all all 127.0.0.1 255.255.255.255 trust
-host all all ::1 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff trust
-host all all ::ffff:127.0.0.1/128 trust
+local all all trust
+host all all 127.0.0.1 255.255.255.255 trust
+# uncomment these to support IPv6 localhost connections
+# host all all ::1 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff trust
+# host all all ::ffff:127.0.0.1/128 trust