[error] (EAI 2)Name or service not known: Could not resolve host
Verificar que el archivo resolv.conf tenga los namservers
vi /etc/resolv.conf
nameserver 64.81.79.2 #speakeasy
nameserver 216.231.41.2 #speakeasy
Solución 2
If you are using static IP, do not use NetworkManager
chkconfig NetworkManager off
service NetworkManager stop
chkconfig network on
service network restart
system-config-network
Fuente: https://www.centos.org/forums/viewtopic.php?t=26327