Windows NT DHCP Server and Win95 DHCP Client

Windows NT DHCP Server and Win95 DHCP Client

Post by Spencer Wong Foo W » Fri, 24 Nov 1995 04:00:00



Hello all,

I am using Windows NT as a DHCP server with a range of IP addresses to
issue say 153.20.70.100 to 153.20.70.120. I have a Win95 client with
hardcoded IP address of 153.20.70.100. Also, I have another Win95
client which is configured to obtain an IP address from the network
using DHCP.

I booted up the Windows NT server and the Win95 client with IP address
153.20.70.100 first. Then, I boot up the Win95 DHCP client and got an IP
address of 153.20.70.100 issue from the Windows NT DHCP server. I got
complaint message of duplicate IP address from both Win95s.

Is this a bug in Windows NT as the algorithm is not according to the
RFC 1531(DHCP). The DHCP server is supposed to send an ICMP echo to check
whether anyone using that IP address before issuing out rite?
Any comments or feedback?  

 
 
 

Windows NT DHCP Server and Win95 DHCP Client

Post by Dave MacDona » Tue, 28 Nov 1995 04:00:00



Quote:

>Hello all,

>I am using Windows NT as a DHCP server with a range of IP addresses to
>issue say 153.20.70.100 to 153.20.70.120. I have a Win95 client with
>hardcoded IP address of 153.20.70.100. Also, I have another Win95
>client which is configured to obtain an IP address from the network
>using DHCP.

>I booted up the Windows NT server and the Win95 client with IP address
>153.20.70.100 first. Then, I boot up the Win95 DHCP client and got an IP
>address of 153.20.70.100 issue from the Windows NT DHCP server. I got
>complaint message of duplicate IP address from both Win95s.

>Is this a bug in Windows NT as the algorithm is not according to the
>RFC 1531(DHCP). The DHCP server is supposed to send an ICMP echo to
check
>whether anyone using that IP address before issuing out rite?
>Any comments or feedback?  

The RFC doesn't require the server to figure out whether there are
other machines using addresses within its scope...statically assigned
addresses musn't overlap the dynamically assigned range.

MS TCP stacks do perform duplicate address detection when they
initialize, regardless of whether they were dhcp configured, or
statically configured.  That's why the client complains.
--
Dave MacDonald
Microsoft Corporate Network Systems
The opinions expressed in this message are my own personal views
and do not reflect the official views of Microsoft Corporation.

 
 
 

Windows NT DHCP Server and Win95 DHCP Client

Post by Spencer Wong Foo Wa » Wed, 29 Nov 1995 04:00:00




> >Hello all,

> >I am using Windows NT as a DHCP server with a range of IP addresses to
> >issue say 153.20.70.100 to 153.20.70.120. I have a Win95 client with
> >hardcoded IP address of 153.20.70.100. Also, I have another Win95
> >client which is configured to obtain an IP address from the network
> >using DHCP.

> >I booted up the Windows NT server and the Win95 client with IP address
> >153.20.70.100 first. Then, I boot up the Win95 DHCP client and got an IP
> >address of 153.20.70.100 issue from the Windows NT DHCP server. I got
> >complaint message of duplicate IP address from both Win95s.

> >Is this a bug in Windows NT as the algorithm is not according to the
> >RFC 1531(DHCP). The DHCP server is supposed to send an ICMP echo to
> check
> >whether anyone using that IP address before issuing out rite?
> >Any comments or feedback?  

> The RFC doesn't require the server to figure out whether there are
> other machines using addresses within its scope...statically assigned
> addresses musn't overlap the dynamically assigned range.

Yes, we understand the RFC and the issue is not only how to detect the
duplicate ip address but, shouldn't the dynamic allocation of network
addresses mechanism of DHCP server allocate those unassigned ip addresses
within the range and yet not used in that subnet to the newly join
workstations?

Quote:

> MS TCP stacks do perform duplicate address detection when they
> initialize, regardless of whether they were dhcp configured, or
> statically configured.  That's why the client complains.

How about some proactive measure (for large network) with "highly
computer literate" end-users? I think M$ should produce a more "foolproof"
DHCP server.

- Show quoted text -

Quote:> --
> Dave MacDonald
> Microsoft Corporate Network Systems
> The opinions expressed in this message are my own personal views
> and do not reflect the official views of Microsoft Corporation.

 
 
 

Windows NT DHCP Server and Win95 DHCP Client

Post by Peter H. Lemie » Sun, 03 Dec 1995 04:00:00




> >complaint message of duplicate IP address from both Win95s.

> >Is this a bug in Windows NT as the algorithm is not according to the
> >RFC 1531(DHCP). The DHCP server is supposed to send an ICMP echo to
> The RFC doesn't require the server to figure out whether there are
> other machines using addresses within its scope...statically assigned
> addresses musn't overlap the dynamically assigned range.

I read Dave's comment as meaning that a well-configured DHCP server
should not include any statically assigned addresses in its range of
available number.  This seems like a reasonable requirement to impose
on the network administrator.  I presume that if you exclude .100
address from the DHCP pool everything works fine?

Peter
-----

cyways, inc.                                          (800) 5-cyways
203 Arlington Street, Watertown, MA 02172          +1 (617) 924-7991
Your source for total Internet solutions(tm)   http://www.cyways.com

 
 
 

Windows NT DHCP Server and Win95 DHCP Client

Post by Brian Lewi » Sun, 03 Dec 1995 04:00:00


In your DHCP scope exclude your static ip numbers or do not include them
in the pool with to begin with.

Brian Lewis


Quote:

> Hello all,

> I am using Windows NT as a DHCP server with a range of IP addresses to
> issue say 153.20.70.100 to 153.20.70.120. I have a Win95 client with
> hardcoded IP address of 153.20.70.100. Also, I have another Win95
> client which is configured to obtain an IP address from the network
> using DHCP.

> I booted up the Windows NT server and the Win95 client with IP address
> 153.20.70.100 first. Then, I boot up the Win95 DHCP client and got an IP
> address of 153.20.70.100 issue from the Windows NT DHCP server. I got
> complaint message of duplicate IP address from both Win95s.

> Is this a bug in Windows NT as the algorithm is not according to the
> RFC 1531(DHCP). The DHCP server is supposed to send an ICMP echo to check
> whether anyone using that IP address before issuing out rite?
> Any comments or feedback?

 
 
 

Windows NT DHCP Server and Win95 DHCP Client

Post by Joe Spea » Wed, 06 Dec 1995 04:00:00



(snip)

Quote:>Yes, we understand the RFC and the issue is not only how to detect the
>duplicate ip address but, shouldn't the dynamic allocation of network
>addresses mechanism of DHCP server allocate those unassigned ip addresses
>within the range and yet not used in that subnet to the newly join
>workstations?

>> MS TCP stacks do perform duplicate address detection when they
>> initialize, regardless of whether they were dhcp configured, or
>> statically configured.  That's why the client complains.
>How about some proactive measure (for large network) with "highly
>computer literate" end-users? I think M$ should produce a more "foolproof"
>DHCP server.

(sig snip)

You mean that if your printer is using an address someone dedicated to
it, but it happens to be turned off when someone requests a DHCP
address and obtains a 30 day lease for the same address (because DHCP
looks for it and sees that it's available), you want the DHCP server
to deny the printer access to its address when it powers up, even
though it's been hardcoded and doesn't request one?

I've got a bridge to sell you.

DHCP and WINS are pretty darn nice to have, even without the
mindreading module (extra charge).

Joe

 
 
 

Windows NT DHCP Server and Win95 DHCP Client

Post by howe.. » Fri, 08 Dec 1995 04:00:00




>  >I booted up the Windows NT server and the Win95 client with IP address
>  >153.20.70.100 first. Then, I boot up the Win95 DHCP client and got an IP
>  >address of 153.20.70.100 issue from the Windows NT DHCP server. I got
>  >complaint message of duplicate IP address from both Win95s.

My complaint with the Microsoft implementation is that after receiving an address conflict, the
DHCP client fails to send a DHCPDECLINE packet, and therefore fails to obtain a valid
address.  This occurs with both Windows95 and Windows for Workgroups with the 3.11b
stack.  Microsoft has confirmed this as a bug.

Cindy

 
 
 

Windows NT DHCP Server and Win95 DHCP Client

Post by Spencer Wong Foo Wa » Sat, 09 Dec 1995 04:00:00




> (snip)
> >Yes, we understand the RFC and the issue is not only how to detect the
> >duplicate ip address but, shouldn't the dynamic allocation of network
> >addresses mechanism of DHCP server allocate those unassigned ip addresses
> >within the range and yet not used in that subnet to the newly join
> >workstations?

> >> MS TCP stacks do perform duplicate address detection when they
> >> initialize, regardless of whether they were dhcp configured, or
> >> statically configured.  That's why the client complains.

> >How about some proactive measure (for large network) with "highly
> >computer literate" end-users? I think M$ should produce a more "foolproof"
> >DHCP server.

> (sig snip)

> You mean that if your printer is using an address someone dedicated to
> it, but it happens to be turned off when someone requests a DHCP
> address and obtains a 30 day lease for the same address (because DHCP
> looks for it and sees that it's available), you want the DHCP server
> to deny the printer access to its address when it powers up, even
> though it's been hardcoded and doesn't request one?

> I've got a bridge to sell you.

> DHCP and WINS are pretty darn nice to have, even without the
> mindreading module (extra charge).

Hello Joe, I am not looking for a hardware to solve this problem.
I am looking for M$ for possible fixes to dat problem.
 
 
 

Windows NT DHCP Server and Win95 DHCP Client

Post by Spencer Wong Foo W » Sat, 09 Dec 1995 04:00:00


Quote:>  >I booted up the Windows NT server and the Win95 client with IP address
>  >153.20.70.100 first. Then, I boot up the Win95 DHCP client and got an IP
>  >address of 153.20.70.100 issue from the Windows NT DHCP server. I got
>  >complaint message of duplicate IP address from both Win95s.

>My complaint with the Microsoft implementation is that after receiving an address conflict, the
>DHCP client fails to send a DHCPDECLINE packet, and therefore fails to obtain a valid
>address.  This occurs with both Windows95 and Windows for Workgroups with the 3.11b
>stack.  Microsoft has confirmed this as a bug.

>Cindy

Thanks Cindy, I am actually expecting M$ staff to reply this. Dunno wat
happen to the M$ staff, MIA in the net.<grin>
Will wait for the bug fixes.