telnetd error: socket: Address family not support protocol

[huangxiangyu at bj.xinwei.com.cn]

Hi all,
I selected the telnetd in busybox1.1.3 according to the help,when I ran
it,the error reported:

telnetd: socket: Address family not support protocol

"netstat -a"：
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 *:ftp                   *:*                     LISTEN
tcp        0      0 *:telnet                *:*                     LISTEN
netstat: no support for `AF INET6 (tcp)' on this system.
netstat: no support for `AF INET6 (udp)' on this system.
netstat: no support for `AF INET6 (raw)' on this system.
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags       Type       State         I-Node Path

"mount":
/dev/root on / type ext2 (rw,nogrpid)
proc on /proc type proc (rw,nodiratime)
devpts on /dev/pts type devpts (rw)

"ls /dev/pt*"：
pts ptmx ptyp0 ptyp1 ptyp2

What's wrong with it,help pls.