[U-Boot-Users] dhcp problems with Windows Server

[Aras Vaichas <arasv@magellan-technology.com>]

Hello,

I'm seeing problems with the DHCP mechanism in U-Boot and the DHCP server on
Windows Server 2000/2003. We use U-Boot 1.2 on an at91rm9200 based platform
with the DM9161 PHY.

Now I understand that this may not be a U-Boot problem, but for the sake of
interoperability it may be a good idea to try and fix it as many people use
Windows Server ...

Normally we use Un*x DHCP servers and I get 100% success rate but with the
Microsoft version of DHCP I see about a 75% success rate. i.e. 1 in 4 requests
will fail.

Looking at the packets with Ethereal, it looks like the DHCP server isn't
sending the final "DHCP ACK" for the "DHCP Request" from the U-Boot. Something
that U-Boot is sending in the "DHCP Request" to the Windows Server is causing
it to fail occasionally.

As a comparison, I used udhcpc from Busybox to make the DHCP request and I get
a 100% success rate.

There are some obvious differences between the requests from the two pieces of
software. (my test Windows Server 2003 DHCP server is on 10.1.1.1 and is
offering 10.1.1.2). As I am not a low level DHCP packet expert, perhaps someone
else can make sense of this. I will also start studying the BOOTP options
fields and try and understand if any of the U-Boot DHCP packet options are
incorrect.


** U-Boot DHCP sequence **

DHCP Discover:
Seconds Elapsed = 1
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Option 53: DHCP Message Type = Discover
Option 57: Maximum DHCP Message Size = 576
Option 55: Parameter Request List
	1 = Subnet Mask
	3 = Router
	12 = Host name
	17 = Root Path

DHCP Request:
Seconds Elapsed = 1
Your (client) IP address: 10.1.1.2 (10.1.1.2)
Next server IP address: 10.1.1.1 (10.1.1.1)
Option 53: DHCP Message Type = DHCP Request
Option 57: Maximum DHCP Message Size = 576
Option 54: Server Identifier = 10.1.1.1
Option 50: Requested IP Address = 10.1.1.2
Option 55: Parameter Request List
	1 = Subnet Mask
	3 = Router
	12 = Host name
	17 = Root Path


** udhcpc DHCP sequence **

DHCP Discover:
Seconds Elapsed = 0
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Option 53: DHCP Message Type = DHCP Discover
Option 61: Client Identifier
	Hardware type: Ethernet
	Client MAC address: ...
Option 60: Vendor class identifier = "udhcp 0.9.9-pre"
Option 55: Parameter Request List
	1 = Subnet Mask
	3 = Router
	6 = Domain Name Server
	12 = Host Name
	15 = Domain Name
	28 = Broadcast Address
	40 = Network Information Service Domain
	41 = Network Information Service Servers
	42 = Network Time Protocol Servers

DHCP Request:
Seconds Elapsed = 0
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Option 53: DHCP Message Type = DHCP Request
Option 61: Client Identifier
	Hardware type: Ethernet
	Client MAC address: ...
Option 60: Vendor class identifier = "udhcp 0.9.9-pre"
Option 50: Requested IP Address = 10.1.1.2
Option 54: Server Identifier = 10.1.1.1
Option 55: Parameter Request List
	1 = Subnet Mask
	3 = Router
	6 = Domain Name Server
	12 = Host Name
	15 = Domain Name
	28 = Broadcast Address
	40 = Network Information Service Domain
	41 = Network Information Service Servers
	42 = Network Time Protocol Servers



regards,

Aras Vaichas

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