Wierd DHCP Problem

[Derek]

Hi folks,

I wonder if any-one can give any tips on a wierd DHCP problem I have with a
customer. Been working on it for 2 weeks now.

He has XPPRO and connects via DHCP to an NT4 Backup Domain Controller. His
p.c. for some reason will not pick up an IP address from the BDC unless the
BDC is re-booted. Yet every other p.c. in the office gets an IP address
fine.

Wasn't too worried as I could configure it with a static IP address, but
that wouldn't work either. he got Limited or no connectivity on his network.
Until I re-booted the BDC and his static IP then worked.

So it could be his machine or it could be the BDC. To test his machine I
scrubbed the hard disk and re-installed XPPRO - exactly the same symptoms. I
tried using a PCMCIA card instead of the internal network port, still the
same symptoms. OK, so it must be the BDC.

Took it off site and connected it to a DHCP router and it picked up an IP
address everytime - no problems at all, did an IPCONFIG /RENEW about 20
times and it worked every time.

My only conlcusion is that in order for this symptom to happen this p.c. AND
this BDC must be together.

What I don't understand though is why having configured the p.c. with a
fixed IP address it has no network connectivity until the BDC is re-booted.
If the BDC is no longer offering it an IP address why should it be blocking
its network access.

As an aside I also tried setting a MAC address reservation on the BDC but
that didn't help change the symptoms.

The whole thing is very wierd. Has any-one seen this before?

P.s. if this is posted to wrong group can you please suggest another group?

Thanks a lot,

Derek

 

[Vagabond Software]

Hi folks,

I wonder if any-one can give any tips on a wierd DHCP problem I have with
a
customer. Been working on it for 2 weeks now.

He has XPPRO and connects via DHCP to an NT4 Backup Domain Controller. His
p.c. for some reason will not pick up an IP address from the BDC unless
the
BDC is re-booted. Yet every other p.c. in the office gets an IP address
fine.

Wasn't too worried as I could configure it with a static IP address, but
that wouldn't work either. he got Limited or no connectivity on his
network.
Until I re-booted the BDC and his static IP then worked.

So it could be his machine or it could be the BDC. To test his machine I
scrubbed the hard disk and re-installed XPPRO - exactly the same symptoms.
I
tried using a PCMCIA card instead of the internal network port, still the
same symptoms. OK, so it must be the BDC.

Took it off site and connected it to a DHCP router and it picked up an IP
address everytime - no problems at all, did an IPCONFIG /RENEW about 20
times and it worked every time.

My only conlcusion is that in order for this symptom to happen this p.c.
AND
this BDC must be together.

What I don't understand though is why having configured the p.c. with a
fixed IP address it has no network connectivity until the BDC is
re-booted.
If the BDC is no longer offering it an IP address why should it be
blocking
its network access.

As an aside I also tried setting a MAC address reservation on the BDC but
that didn't help change the symptoms.

The whole thing is very wierd. Has any-one seen this before?

P.s. if this is posted to wrong group can you please suggest another
group?

Thanks a lot,

Derek

Since the problem seems to clearly lie with the server, you might try:

microsoft.public.windows.server.general

Does the workstation show up under Address Leases on the server's dhcpmgmt
console? How about after doing a ipconfig /release and ipconfig /renew on
the client? You do have IP addresses remaining in the Address Pool?

Also, you may want to run ipconfig /all on the client and compare that to an
ipconfig /all on another client that is working fine. Make sure dhcp and
autoconfigure are enabled. Confirm your dhcp server is listed correctly.
Make sure there are no hard coded addresses in the Network Connection
Properties dialogs (such as Gateway).

Good Luck,

carl

 

[Derek]

Carl,

Believe it or not about 30 minutes after posting this message I got to the
bottom of this.

I knew there had to be something common in the office setup that I was
missing. The only common thing was the switch. All users go through the same
switch.

Changing ports on the switch didn't make any difference, but re-booting the
switch seems to have fixed it. I have no idea why especially when re-booting
the BDC seemed to offer him an IP, only thing I can imagine is that a BDC
re-boot sends some sort of broadcast through the switch that allowed him a
one time IP address. However now that the switch itself has been re-booted
he can get an Ip address every time and the problem seems to be solved.

All the best,
Derek