For those reading in the wings, DHCP works like this: The client and the server normally send and receive DHCP messages in the following order: ** new lease (all broadcast traffic) ** Client ( Discover ) --> Server Server ( Offer ) --> Client Client ( Request ) --> Server Server ( Ack ) --> Client ** client has a new IP! ** ** lease renewal (normal IP traffic) ** Client ( Request ) --> Server Server ( Ack ) --> Client ** client has the same IP! ** What typically happens (in the few traces I've been sent, anyway) is that the client tries to renew its IP with a DHCP "Request", but is answered by a DHCP "Nak" from the server, causing it to start the lease process from scratch. Since ISA doesn't allow broadcast traffic at the external (RED, North) interface, the DHCP Offer is never seen by the ISA's DHCP client service and the lease attempt fails. ..just a theory, you understand... Jim Harrison MCP(NT4, W2K), A+, Network+, PCG http://isaserver.org/authors/harrison/ Read the books! ----- Original Message ----- From: "David" <david_agner@xxxxxxxxxxx> To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx> Sent: Monday, April 01, 2002 9:17 AM Subject: [isalist] Re: DHCP / BOOTP problems when geting IP from ISP (Telia) http://www.ISAserver.org DHCP works if I connect the "RED" interface to my local DHCP server and the filters are ok. I had this problem earlyer when using a Linux FW " floppyFW" any one familyar wiht this problem ? ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jim@xxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub')