RE: Preventing DHCP from allocating IPs

["Rick Darsey" <rdarsey () aims1 com>]

I know this sounds like a really bad way of doing this, but it is the only
way I can come up with off the top of my head:

Turn of DHCP!! Statically assign all addresses in your LAN. If a visitor
wants access to your network, they will have to come to you to obtain the
address, or better yet, create a small DHCP pool that visitors can use, but
limit the size to prevent users you do not want from accessing the network.
The initial setup of the static addresses will take time, but the small DHCP
pool will still allow visitors to plug in when needed.

Rick

-----Original Message-----
From: jon kintner [mailto:jon.kintner () lvcm com]
Sent: Monday, December 02, 2002 1:04 PM
To: ssgill () gilltechnologies com; security-basics () securityfocus com
Subject: Re: Preventing DHCP from allocating IPs


I know mac addresses can be spoofed pretty easily, but could you setup an
access list or filter that would disallow all mac addresses except for the
ones specified on your network(s)?
The initial setup would probably be tedious, but it's worked fairly well to
keep most unauthorized logins off the network at the college I attend.

-jon kintner

----- Original Message -----
From: "Sarbjit Singh Gill" <ssgill () gilltechnologies com>
To: <security-basics () securityfocus com>
Sent: Monday, December 02, 2002 7:22 AM
Subject: Preventing DHCP from allocating IPs


> Greetings all,
>
> How do i prevent a client from getting an IP from my DHCP in an Ethernet
> network. I know i could reserve IPs for all other clients and nobody gets
an
> IP unless reserved earlier, but i have hundreds of clients. I frequently
> have visitors who need to plug in their laptops into the network and i
have
> visitors who are not allowed to plug in their laptops into the network and
> get IPs. I do not want these visitors who are not allowed to access the
> network to get an IP and start accessing internet through my network.
>
> What about in a wireless environment. How do i prevent it in a similar
> capacity.
>
> Kind Regards
> Gill