编辑/etc/gai.conf

找到如下部分,取消前5行的注释

# label   <mask>   <value>
#    Add another rule to the RFC 3484 label table.  See section 2.1 in
#    RFC 3484.  The default is:
#
label ::1/128       0
label ::/0          1
label 2002::/16     2
label ::/96         3
label ::ffff:0:0/96 4
#label fec0::/10     5
#label fc00::/7      6
#label 2001:0::/32   7