On Wed, Dec 22, 2010 at 11:17 PM, Aravindh Ramaswamy <aravindhramu at gmail.com> wrote: > Sir/Madam, > > This is Aravindh,final year student of Anna University India.We are carrying > on research in Cloud Computing and using Open Nebula toolkit for that;for > which we need strong network connectivity. The problem i am facing is that i > am not able to ping continuously to other nodes in the network. The > connectivity is getting lost after 2-3 minutes. we have inspected the > connectivity links , switch etc. and found them to be normal. In fact it > pings continuously in other OS. Is there any problem in CentOS network > connectivity packages? Help needed urgently.. Pinging continuously can be detected by some firewall as part of denial-of-service attack, which can then block ICMP packages, even block them selectively. How often are you pinging, and from how many other nodes?