The Baiduspider crawls the web sites continuously like ddos attack and causing the bandwidth issue at that time ,we can block the Baiduspider by using the following iptables rule to block the Baiduspider server wide.
iptables -p tcp -I INPUT -j DROP -s 119.63.192.0/21
iptables -p tcp -I INPUT -j DROP -s 123.125.64.0/18
iptables -p tcp -I INPUT -j DROP -s 180.76.0.0/16
iptables -p tcp -I INPUT -j DROP -s 220.181.0.0/16