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Re: Down with DHCP!!!!
From: Kenton Smith <listsks () yahoo ca>
Date: Fri, 17 Feb 2006 20:01:16 -0500 (EST)

I say bad idea. There are other ways (I think) to
solve the issue without creating friction with other
groups. As soon as you go and mandate something that
is going to add work for other people you're going to
become an enemy and they're going to try to bypass you
at every opportunity. With that many users I think
going to staic IP's would be a management nightmare
(speaking as someone who managed a static IP network
of 225 users).

Why don't you use MAC addresses for your inventory? Or
use DNS? You've got the MAC address to check to make
sure that the machine is who it says it is. Use the
name to hav a more friendly way of inventorying.

As for preventing someone from putting a machine on
the network, what's to stop them from giving their
machine a static IP on your network? If you use MAC
addresses there are a multitude of tools available to
prevent users from adding machines to the network.

Security is always a compromise; if you don't
compromise in certain places you're going to spend
more of your time policing the people who are trying
to get around your less important security measures
and less time actually keeping the really important
stuff secure.

Kenton

--- gigabit () satx rr com wrote:

ok, some background...

i have transfered from network engineering to the
information security 
group for my company, which is mid-sized with about
2000 employees 
across 90 locations (financial).

the lessons learned from being in network
engineering is that they are 
first and foremost concerned with maintaining the
production 
environment.  the management processes/procedures
are completely 
disregarded if it is deemed necessary to "get
something done".

as i try to build out a security plan for how to
deal with 
servers/routers/end users, i keep coming to the
conclusion that it will 
be meaningless unless control can be taken over what
the other 
department is doing (network engineering).  the one
commonality for all 
devices on the network is that they have an IP
address.

i would like to propose to management that dhcp
should be disabled, so 
as to force the building of a database that will
hold all of the 
information needed to begin a comprehensive security
policy.  the 
security group would manage the database to ensure
that we are 
collecting information (such as O/S, IOS version,
anti-virus 
compliance...)

i realize this will incur more work for those poor
souls that have to 
deploy hardware, but i believe the benefits
out-weigh the costs.  the 
benefits i see:

1.  once a branch location is staticly addressed, we
have a working 
inventory of what is out there.

2.  a more secure environment.  no longer can users
bring in non-
company owned devices and place them on our
production network (which 
is already a policy---that isn't policed).

3.  i can setup automated scripts that check MAC
addresses to IP 
addresses on the router ARP tables to check for
spoofing.

our branch locations don't change very
often.....some are still on 
token ring for god's sake, so i don't really see
that much more 
workload.

Has anyone else dropped DHCP as a
management/compliance decision?

thanks.


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---------------------------------------------------------------------------
EARN A MASTER OF SCIENCE IN INFORMATION ASSURANCE - ONLINE
The Norwich University program offers unparalleled Infosec management 
education and the case study affords you unmatched consulting experience. 
Tailor your education to your own professional goals with degree 
customizations including Emergency Management, Business Continuity Planning, 
Computer Emergency Response Teams, and Digital Investigations. 

http://www.msia.norwich.edu/secfocus
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