[CentOS] dhcpd and centos 7 network burps

Sat Jan 9 01:55:48 UTC 2016
david <david at daku.org>


I have noticed that my Centos 7 systems which use DHCPD from a router 
or gateway all seem to fail when the DHCP client asks for a 
renewal.  After issuing
   systemctl restart NetworkManger
the connectivity resumes until the lease renewal time occurs again.

As part of my research, I set up a CRON job that runs every five 
minutes, and uses
  ip route
to determine what my IP address is.  When it fails to get an address, 
it issues the restart NetworkManager.

This problem seems to occur on various DHCPD servers, but the 
30-minute regularity is surprising.

Is there an issue with the DHClient and the renewal process whereby 
it looses connectivity?

Centos 6 and Windows have no problem using the same DHCP server.