Not being able to distinguish between a valid client or not from a network perspective makes it pretty hard. You can easily stop this accross the board (with a router, etc).
It may be a bit more of a hassle but if you know the valid clients MAC address ahead of time you could filter out that way as well. However its not foolproof against a malicious person intent on gaining access. In regards to wireless, outside from the above I have seen implementations that use a VPN connection that must be established before you can access any network resources. -Jimmy -----Original Message----- From: Sarbjit Singh Gill [mailto:[EMAIL PROTECTED]] Sent: Monday, December 02, 2002 10:46 AM To: [EMAIL PROTECTED] 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