配置完iptables，ha总会报错然后重启。把心跳的端口加入配置也没用：
iptables -A INPUT -p udp -m udp --dport 1120 -j ACCEPT
错误如下：
Message from syslogd@db1 at Mon Nov 25 10:29:48 2013 ...
db1 hb[4408]: <emerg> REBOOT gently after 1 seconds: do_heartbeat: cannot connect to the third IP and partner node, reboot local node now...
Broadcast message from root (Mon Nov 25 10:29:49 2013):
do_heartbeat: cannot connect to the third IP and partner node, reboot local node now...
The system is going down for reboot NOW!