Address family not supported by protocol

root@gbos:~# wget
--04:12:31-- 
           => `wget-1.11.tar.gz'
Resolving ftp.gnu.org... 140.186.70.20
Connecting to ftp.gnu.org[140.186.70.20]:80... failed: Address family not supported by protocol.
Retrying.

run stace to look into:


write(2, "Connecting to ftp.gnu.org[140.18"..., 47Connecting to ftp.gnu.org[140.186.70.20]:80... ) = 47
socket(PF_INET6, SOCK_STREAM, IPPROTO_IP) = -1 EAFNOSUPPORT (Address family not supported by protocol)
write(2, "failed: Address family not suppo"..., 50failed: Address family not supported by protocol.

in my os,don't support ipv6