Hello, I configure freeradius to be a unicast dhcp server for working with Cisco ASR. client --> cisco relay -> freeradius My configuration is: dhcp DHCP-Discover { if ( "%{mms: ${..ip_query}}" ) { update reply { DHCP-Message-Type = DHCP-Offer } update reply { &DHCP-Your-IP-Address = "%{mms: ${....ip_query} }" &DHCP-Subnet-Mask = "%{mms: ${....mask_query} }" &DHCP-Router-Address = "%{mms: ${....gw_query} }" &DHCP-Domain-Name-Server = "%{mms: ${....ns1_query} }" &DHCP-Domain-Name-Server += "%{mms: ${....ns2_query} }" &DHCP-IP-Address-Lease-Time = _DHCP_LEASE_TIME_ } ok } else { update reply { &DHCP-Message-Type = DHCP-Do-Not-Respond } reject } } dhcp DHCP-Request { update reply { &DHCP-Message-Type = DHCP-Ack } update reply { &DHCP-Your-IP-Address = "%{mms: ${...ip_query} }" &DHCP-Subnet-Mask = "%{mms: ${...mask_query} }" &DHCP-Router-Address = "%{mms: ${...gw_query} }" &DHCP-Domain-Name-Server = "%{mms: ${...ns1_query} }" &DHCP-Domain-Name-Server += "%{mms: ${...ns2_query} }" &DHCP-IP-Address-Lease-Time = _DHCP_LEASE_TIME_ } ok } This is working, but my concern is, if client's mac adres is not in the database, they dhcp client will send dhcp-discovery all the time, and one discovery = one sql query. Is there any way to prevent that? Some cache or so? Thanks for help.