DHCP Duplicate IP

[=?iso-8859-1?Q?Gollner_G=FCnther?=]

we get duplicate IP's when we power up 10 PC's at the
same time (also the router which is the DHCP Server).

Example DHCP Packets:

1. PC: DHCP Discover
2. Router: DHCP Offer Client IP=192.111.111.5
3. PC: DHCP Request Client IP=192.111.111.7
4. Router: DHCP NAK

so the XPE Client tries to get a different IP than the
Server offers. Some of the PC's restart DHCP
communication and get a correct IP. But others simply use
the requested wrong IP which is already used by a
different PC.

When the lease is refreshed the PC's get and use correct
IP's.

We tried Linksys and Netgear Routers with the same Result.

 

[Heidi Linda]

Have your machines been resealed, or are they all using
the same identification? That will mess up your
networking...

 

[=?iso-8859-1?Q?G=FCnther_Gollner?=]

no reseal because i run from writeprotected media with
ram overlay.
there is no Microsoft Client on XP only tcp/ip protocol,
so there shouldn't be a problem of same Computernames.

only 2-3 of 12 PC's have this problem, all with the same
image. with leasetime set to 5 mins, after the 1st
refresh all PC's get different IP's.

 

[Heidi Linda]

Fair enough, I thought I'd seen a reference to not
resealing causing network problems, but it probably was to
do with the computer name.
I know resealing has more effect than just the machine's
name, however.

 

[Doug Hoeffel]

Are these 10 pc's on a domain? If you don't reseal then all 10 have the
same SID. I don't think this is a good thing to do on a domain.

I would reseal to change atleast the SID.

HTH... Doug

 

[Andy Allred [MS]]

Doug's right. If they all have the same SID then there's no surprise that
you're having networking problems. Try cloning the image, redeploy them and
see if that resolves the issue.

Thanks

 

[=?iso-8859-1?Q?G=FCnther_Gollner?=]

i'll try this today,

if this is the problem, then i have a question:

how should i make 10.000+ different resealed images,
let's say on something similar to a cd-rom or a prom.
(i can only write ONE time to the media, which takes
about 30 minutes per media)

the second problem is, the customers are running tests
(crc checks, md5 hash) on the complete media, to make
sure nothing is changed !(manipulated)

when i start the PC'S one by one, delay about 5 sec
(walking from on to another) it works. Only when i start
all of the PC's the same time, most of the time (4 out of
5) this problem occurs. if i restart the bad PC's, they
get a correct IP.

and again there is NO Network Client on the PC, also no
Domain, only TCP/IP protocol. i don't get duplicate
Computernames, only duplicate ip.

the network sniffer tells me a dhcp-request with an IP,
which is different from the dhcp-offer for this MAC-
address.

There are no SID informations in DHCP-Packets, so how can
this make troubles ?
How are operating systems without SID's getting DHCP IP's?
Why does MS don't use Computernames from DHCP ?
What means DHCP Option 249, why only MS-DHCP recognizes it
(all others ignore it) ?

Ex:

PC 1: DHCP Discover
PC 2: DHCP Discover
DHCP offer: ip:1.2.3.4 -> PC1
DHCP offer: ip:1.2.3.5 -> PC2(so PC2 should take 1.2.3.5)
PC 1: DHCP Request ip:1.2.3.4
DHCP ACK -> PC1
PC 2: DHCP Request ip:1.2.3.4(but it requests th wrong)
DHCP NACK -> PC2

the MAC-Addresses in the Packets are for the correct PC.

thx

 

[Doug Hoeffel \(eMVP\)]

Gollner:

Did you resolve this?

.... Doug
now i have resealed the Images and the problem still
persists, any ideas ?

 

[Polux]

This problem is due to a bug in Microsoft client DHCP in dhcpcsvc.dll. XP
Pro is concerned too.
Several clients could take the same DHCP Offer because they have the same
DHCP xid.
A fix has been made last week to correct the xid generation. I don't know if
it is publicly released but it will be added to XP SP2.