辞書攻撃の対策として非常に有効です。 hosts.allow sshd : ALL : spawn ( /usr/local/bin/block_ssh_attack.sh %a 5 ) : allow /usr/local/bin/block_ssh_attack.sh #!/bin/sh # arg1 : ip addr ( can be given by tcpd ) # arg2 : suspend time in minutes export NUMLOGBACK=30 export LOGFILE=/var/log/auth.log export WHITELIST="hostb.example.org" export MAILCMD=mail export IPADDR=$1 export SUSPENDMIN=$2 whitelist() { #echo "checking