Why sometimes there is no access to the server?

Question

CentOS

Every 5 minutes the server on Centos 6.5 becomes unavailable, although the modem is pinging, what could be the problem? Perhaps something with the provider or with the server itself?
The server is not the weakest, xeon, 10GB of RAM, etc.
Thank you.

Answer 1

although the modem is pinging

What is a modem? Ordinary analog?
Most likely something with a connection, but there are few details describing the situation.

Answer 2

only with your internet is not available? work, sister, brother at work.. complain? Half of the answer, and it will be clear where to dig.

Answer 3

The load on the server does not rise every 5 minutes?
Can that in cron is started constantly?

Answer 4

install munin or nagios and monitor all processes on the server and ping.