DHCP-server + MAC

в dhcpd.conf deny unknown-clients;

Или прописать только статические записи, а range сообще не назначать.

subnet 10.0.0.0 netmask 255.255.255.0
{ 
  option routers 10.0.0.1;
  option subnet-mask 255.255.255.0;
  option broadcast-address 10.0.0.255;

        host ws10 { hardware ethernet 00:11:22:33:44:55;  fixed-address 10.0.0.10;      option host-name "ws10"; }
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}