block an attacking IP address with IPtables

Here's what was going on:

Oct 8 20:53:08 cheap-dell sshd[27592]: Disconnecting: Too many authentication failures for root [preauth]
Oct 8 20:53:08 cheap-dell sshd[27592]: PAM 5 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=217.30.65.218.broad.xy.jx.dynamic.163data.com.cn user=root
Oct 8 20:53:08 cheap-dell sshd[27592]: PAM service(sshd) ignoring max retries; 6 > 3
Oct 8 20:53:11 cheap-dell sshd[27596]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=217.30.65.218.broad.xy.jx.dynamic.163data.com.cn user=root
Oct 8 20:53:13 cheap-dell sshd[27596]: Failed password for root from 218.65.30.217 port 17122 ssh2
Oct 8 20:53:29 cheap-dell sshd[27596]: message repeated 5 times: [ Failed password for root from 218.65.30.217 port 17122 ssh2]
Oct 8 20:53:29 cheap-dell sshd[27596]: error: maximum authentication attempts exceeded for root from 218.65.30.217 port 17122 ssh2 [preauth]
Oct 8 20:53:29 cheap-dell sshd[27596]: Disconnecting: Too many authentication failures for root [preauth]
Oct 8 20:53:29 cheap-dell sshd[27596]: PAM 5 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=217.30.65.218.broad.xy.jx.dynamic.163data.com.cn user=root
Oct 8 20:53:29 cheap-dell sshd[27596]: PAM service(sshd) ignoring max retries; 6 > 3

Here's what I did (history): (some deleted because of repetition) (I was in /var/logs)

69 cat auth.log | tail
70 > auth.log
71 cat auth.log
75 iptables -A INPUT -s 221.229.172.97 -j DROP <----this is the code to block an IP address in iptables
76 cat auth.log
77 cat auth.log
81 iptables -A INPUT -s 218.65.30.217 -j DROP
82 cat auth.log
83 > auth.log
87 cat auth.log
88 history