################### edns-client-subnet  ###########
wget ftp://ftp.isc.org/isc/bind9/9.9.3/bind-9.9.3.tar.gz
tar xf bind-9.9.3.tar.gz
cd bind-9.9.3
wget http://wilmer.gaa.st/edns-client-subnet/bind-9.9.3-dig-edns-client-subnet-iana.diff
yum -y install patch
patch -p0 < bind-9.9.3-dig-edns-client-subnet-iana.diff
./configure --without-openssl
make
测试
./bin/dig/dig @ns1.google.com www.google.es +client=157.88.0.0/16
./bin/dig/dig  test001.i.com  +client=211.12.1.1    

##ping工具
1. http://ping.chinaz.com
2. http://tools.cloudxns.net/index/mdig