title: Why CentOS lost its network interface?
body: <p>I have a CentOS 7 VPS which I had multiple sites on its Apache, and these days I faced a strange problem, CentOS lost its interface many times a day! and I should restart the interface to recover this situation! I've take a snapshot from Web console interface of my VPS, any idea? thanks in advance<img src="https://i.stack.imgur.com/s8WSn.png" alt="CentOS 7 lost interface!"></p>
  
  <p><code>grep dhclient /var/log/messages </code> ferquently give me this error (also I have <code>BOOTPROTO="dhcp"</code> in my config file) :</p>
  
  <p><code>Apr 30 15:12:56 vultr dhclient[8962]: dhclient.c:2676: Failed to send 300 byte long packet over fallback interface.
  Apr 30 15:13:15 vultr dhclient[8962]: DHCPREQUEST on eth0 to 169.254.169.254 port 67 (xid=0x5f5ca74d)
  Apr 30 15:13:15 vultr dhclient[8962]: send_packet: Network is unreachable
  Apr 30 15:13:15 vultr dhclient[8962]: send_packet: please consult README file regarding broadcast address.
  </code></p>