Security Policy based on Subnet

Question

We are implementing a security policy and Firewall access rules based on the subnet using static dhcp bindings.

There is one scenario where some one can manually assign ip address from a subnet with higher access privileges.

Any suggestion how to cater for such eventuality.

Answer 1

Ideally you would have physical control of the machines on the network and disallow regular users from configuring networking.

If anyone can just come and plug in you will need to look at things like whitelisting mac addresses in the network switches.

Also, take a look at 802.1X if you don't mind a complicated setup

Answer 2

If your networking equipment (switches/routers) supports it, you should consider using a separate VLAN for each subnet.

This will mean that each subnet is logically separated and that users who change their IP address will be unable to establish connections, as return packets will be routed somewhere else.

You should also make sure you turn on ingress filtering on your routing equipment.