ssh 不能连上服务器 hosts.deny没有没限制ip 找不到什么原因

[root@NB Downloads]# ssh -p22022 -vv .5x.xx.xxx
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips  Feb
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv
debug1: Connecting to .xx.xxx.xx [123.57.xx.xxx] port .
debug1: Connection established.
debug1: permanently_set_uid: /
debug1: identity file /root/.ssh/identity type -
debug1: identity file /root/.ssh/identity-cert type -
debug1: identity file /root/.ssh/id_rsa type -
debug1: identity file /root/.ssh/id_rsa-cert type -
debug1: identity file /root/.ssh/id_dsa type -
debug1: identity file /root/.ssh/id_dsa-cert type -
debug1: identity file /root/.ssh/id_ecdsa type -
debug1: identity file /root/.ssh/id_ecdsa-cert type -
ssh_exchange_identification: Connection closed by remote host

# cat /etc/hosts.allow
#
# hosts.allow    This file contains access rules which are used to
#        allow or deny connections to network services that
#        either use the tcp_wrappers library or that have been
#        started through a tcp_wrappers-enabled xinetd.
#
#        See 'man 5 hosts_options' and 'man 5 hosts_access'
#        for information on rule syntax.
#        See 'man tcpd' for information on tcp_wrappers
#
sshd:all #加上这一行问题解决

但这样不安全所有的被禁掉的ip都 可以再会失效果!!!!