We have some HAProxy/keepalived clusters on CentOS7 and found that the virtual IPs managed with keepalived have registered in DNS. Does anyone know of a way to block dns registration for address registered with keepalived or to block DNS registration for an interface (while leaving DHCP on)?
Probably your CentOS servers are sending the hostname to the DHCP server and this is updating the DNS. One way to disable it is using nmcli (use
ipv6.dhcp-send-hosname if you are using IPv6):
nmcli c m "System eth0" ipv4.dhcp-send-hostname no
You must set that configuration for all the connections (you can list them with
nmcli c s -a).
I believe that should solve your issue but if you are still having the problem, could you please provide more information about the DHCP server?