Re: PXE and DHCP

From: Phillip Windell (_at_.)
Date: 05/27/04 

Date: Thu, 27 May 2004 08:51:11 -0500

Excellent! I'll have to keep a copy of those links. 

-- 
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
"Jetro" <no.spam@internet> wrote in message
news:ObMIPF%23QEHA.556@tk2msftngp13.phx.gbl...
> http://support.microsoft.com/default.aspx?scid=kb;EN-US;244036
> Description of PXE Interaction Among PXE Client, DHCP, and RIS Server
>
> http://support.microsoft.com/?kbid=259670
> Using DHCP Options 60, 66, 67 to Direct PXE Clients to RIS Servers May
Fail
>
> When the machine boots using PXE, the boot ROM gets an IP address using
> DHCP. It's then sending out a modified DHCP Discover packet with its GUID.
> The BINL service on a RIS server listens for these special DHCP Discover
> packets and responds with a DHCP Offer packet that includes a copy of the
> client's GUID, but no IP address. The PXE client replies with a DHCP
Request
> packet sent directly to the BINL service on UDP port 4011. The BINL
service
> responds with a DHCP Ack packet that contains the name and path of the
boot
> image, startrom.com.
>  In a routed network, an IP helper field in the router contains the IP
> address of a DHCP server. When the router receives a DHCP Discover packet,
> it forwards the packet to the DHCP server and then acts as an intermediary
> between the server and the DHCP client. If the RIS server is also a DHCP
> server, this works fine. The server returns a single DHCP Offer packet
with
> the client's GUID in the payload and the client handles the rest. If the
> DHCP server and RIS server are on different machines in the same broadcast
> segment as the PXE client, the process also proceeds without problems.
> If, however, the RIS server and the DHCP server are on different machines
> that don't reside in the same broadcast segment as the PXE client, both
> servers must be included in the IP helper field at the router, and you
must
> verify that both servers get the DHCP Discover packet from the router.
> If you have more than one RIS server, don't install RIS on a DHCP server.
A
> PXE client that gets a standard DHCP Offer that contains its GUID won't
> listen for responses from any other RIS servers.
> Because BINL is actually a modified DHCP service, it must be authorized in
> AD.
>
>

Relevant Pages

  • Packet cap diff... for classic dhcp over winxp s/w bridge prob.
    ... the server simultaneously. ... DHCP Discover - Transaction ID 0xe5448fbb ... Time delta from previous packet: ... Time since reference or first frame: ...
    (comp.os.linux.networking)
  • Re: Regarding dhcp client problem
    ... I have captured the packet information from the device. ... win2k dhcp server sends ... But the dhcp client in the device is not receiving the offer at ... User Datagram Protocol, Src Port: bootpc, Dst Port: bootps ...
    (comp.arch.embedded)
  • Re: DHCP serving more than one subnet (longish)
    ... >>destination address is all ones (which means it is a broadcast packet). ... > Responses from the server however rely on the ethernet address only since ... DHCP works over media other than ethernet. ... the case if the request is relayed through a router]. ...
    (comp.os.vms)
  • RE: PXE Client could not get IP from DHCP Server
    ... Are the PC's that you are trying to PXE boot on the same subnet as the RIS ... The reason I as is that you will need to add options 66 and 67 to your DHCP ... target server. ...
    (microsoft.public.windows.server.general)
  • RE: Does RIS require a Microsoft DHCP server?
    ... Since I can't ever change that, I won't be able to use RIS since the DHCP ... server will point any PXE device, even a PC, at the phone server and the RIS ...
    (microsoft.public.windows.server.general)