Folks

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.

David