Re: Linksys assigned IP to unknown DHCP client???

From: aladin (aladin168@hotmail.com)
Date: 11/16/02


From: aladin168@hotmail.com (aladin)
Date: 16 Nov 2002 08:07:13 -0800

I understand the broadcasting part, that's not the problem.

My problem is that why DHCP client table shows my Linksys assigned
IP's that were out of the range I assigned?

Linksys showed the following DHCP client IP while I assigned my DHCP
client IP range as 192.168.1.100 - 149:

        194.168.1.118 00-00-20-08-00-01
  ` 208.168.59.103 00-02-68-20-00-00
        192.168.169.105 01-02-6A-62-10-02

Also, the CLIENT HOSTNAME field were either not showing up or showing
some junks.

Any idea?

Thanks,
/Kyle
kyle@kylelai.com
www.kylelai.com

roberson@ibd.nrc.ca (Walter Roberson) wrote in message news:<ar4rmk$lm6$1@canopus.cc.umanitoba.ca>...
> In article <bf0f8e77.0211151950.347fc074@posting.google.com>,
> aladin <aladin168@hotmail.com> wrote:
> :I have noticed that my DHCP clients table has been showing UNKNOWN
> :DHCP clients!!! I only have 2 computers using my cable modem, but on
> :the DHCP clients table, it showed weird IP addresses that are outside
> :of the DHCP IP range I assigned. The MAC address seems to be spoofed
> :too... Any exploits out there for this type of behavior?
>
> My understanding is that cable modems see all the broadcasts
> for the entire block/group served by the common copper trunk
> but filter the non-broadcast traffic except to your assigned IP.
>
> The implication would be that you would be seeing MAC addresses
> for a number of machines that you wouldn't be able to reach by IP.
>
> I understand that this broadcast behaviour is necessary in order
> to support establishing the session in order to get an IP address
> to work with.
>
> I am not a cable modem user; I've merely seen the behaviour mentioned
> before.