Finally I've found the solution. Here it is: 1. added 2 lines to dictioanry.dhcp ATTRIBUTE DHCP-Option-252 252 octets VALUE DHCP-Parameter-Request-List DHCP-Option-252 252 2. tuned DHCP-Inform section dhcp DHCP-Inform { update reply { Packet-Dst-Port = 67 DHCP-Message-Type = DHCP-ACK DHCP-DHCP-Server-Identifier = "%{Packet-Dst-IP-Address}" DHCP-Option-252 = 0x0a00 } ok } This configuration made win7 to shut up. It turnes out that yesterday I forgot to add "Packet-Dst-Port = 67" ( clients get their addresses via relay ) option to DHCP-Inform section. So, the question about "https://tools.ietf.org/html/draft-ietf-dhc-dhcpinform-clarify-06" does not make sense any more. FR works just like in this draft.