Solved

DHCP, scope problem

Posted on 1997-07-16
6
277 Views
Last Modified: 2013-12-23
I have set up a DHCP server with the range of 192.168.1.50 to 192.168.1.254 on a class C, also I have excluded 192.168.1.200 to 192.168.1.215.  The server has been assigning IP numbers just fine until it reached 80 and then it skipped to 178.  It is now up to 246 and i'm not sure what will happen when it hits 254.  Can someone tell me if this is a problem and what I might do to fix it?
 Thanks,
    neal
0
Comment
Question by:neal
6 Comments
 

Expert Comment

by:gaucig
Comment Utility
What Services pack / NT Version are you running ?
0
 

Author Comment

by:neal
Comment Utility
It's NT 4.0 and I have not installed any service packs yet...
I had SP1 installed but had to switch servers and never have reinstalled, I was also leary of SP2 and havn't touched it either.

neal
0
 

Expert Comment

by:rburrows
Comment Utility
I'd recommend sp2 at least. It contains a lot of DHCP
fixes including dealing with bad addresses.

The question is , even when it jumps to 178 does the number of available addresses tally. (ie. the range less your exclusions)..?

It should start at the lowest possible address and give the first available address it can find. The jump you described seems odd, and may be fixed by one of the S'packs. If it gets to 254 , it will scan the whole range for an available address , not just the next few in the range.
0
Free Trending Threat Insights Every Day

Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

 
LVL 7

Expert Comment

by:Eric B
Comment Utility
Go into dhcp config and check available addresses left. That will tell you if the skip is random or if it skipped for a reason.
0
 
LVL 1

Expert Comment

by:johnsm
Comment Utility
What mask are you using?
0
 

Accepted Solution

by:
gaucig earned 100 total points
Comment Utility
This is a Known Problem from Microsoft see bellow....

PRB: DHCP Skips Addresses If Exclusion Range Included in Scope

Last reviewed: April 4, 1997
Article ID: Q140989 The information in this article applies to:

•Microsoft Windows NT Server versions 3.5 and 3.51 •Microsoft Windows NT Server version 4.0







SYMPTOMS

When you use an exclusion range with DHCP, addresses offered to clients may not begin at the first address in the scope.





STATUS

This behavior is by design.





MORE INFORMATION

Leases offered to clients from a DHCP scope will be offered consecutively, starting with the first address in the IP address pool. But if an exclusion range is added to the scope, the first lease offered may not be the first address in the IP address pool.

For example, if a scope is created using a starting address of 165.224.113.11 and an ending address of 165.224.113.249, the first lease address offered to clients will be 165.224.113.11.

Alternatively, if an exclusion range of 165.224.113.100 to 165.224.113.120 is added to the scope, the first lease address offered will be 165.224.113.75. Leases will be offered consecutively through 165.224.113.249, skipping the excluded range. After 165.224.113.249, the next leases offered will be 165.224.113.11 through 165.224.113.74 consecutively.

This may also occur when multiple ranges of addresses are included in the DHCP scope.
0

Featured Post

Highfive + Dolby Voice = No More Audio Complaints!

Poor audio quality is one of the top reasons people don’t use video conferencing. Get the crispest, clearest audio powered by Dolby Voice in every meeting. Highfive and Dolby Voice deliver the best video conferencing and audio experience for every meeting and every room.

Join & Write a Comment

Downtime reduced, data recovered by utilizing an Experts Exchange Business Account Challenge The United States Marine Corps employs more than 200,000 active-duty Marines with operations in four continents, all requiring complex networking system…
This article offers some helpful and general tips for safe browsing and online shopping. It offers simple and manageable procedures that help to ensure the safety of one's personal information and the security of any devices.
In this seventh video of the Xpdf series, we discuss and demonstrate the PDFfonts utility, which lists all the fonts used in a PDF file. It does this via a command line interface, making it suitable for use in programs, scripts, batch files — any pl…
This video demonstrates how to create an example email signature rule for a department in a company using CodeTwo Exchange Rules. The signature will be inserted beneath users' latest emails in conversations and will be displayed in users' Sent Items…

728 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

15 Experts available now in Live!

Get 1:1 Help Now