What is NAC?
NAC is a method to control and allow only authorized devices to be connected to the network. It is more common for wired network and devices connecting with a hard-wire or a virtual interface to the network. Most wireless networks already have certain access controls available and enforced via 802.1X, WPA to ensure only authorized users or devices can connect to the wireless network.
In a wired network or a standard Ethernet switch, by default, you can connect any device to the network and obtain access. Most networks have a DHCP infrastructure running which provides an IP address to a newly connected device. This makes a wired network vulnerable as an intruder also can physically connect to the network once they get physical access to the premises. An intruder even can find the IP address details of the network in case of absence of a DHCP server in the network.
As per enterprise security best practices and ISO 27001 standards, network policies should be in place and enforced...
