The Management Plane Access Control (MPAC) feature protects network device security. Network devices use the MPAC policies to filter the packets to be sent to the CPUs and discard the unexpected packets to prevent malicious attacks.
On an enterprise network, user-side interfaces need to send a large number of packets to the CPUs of network devices. The frequently sent packets may be attack packets targeting at CPUs. If excess packets are sent to the CPU of a device, the CPU usage becomes high and CPU performance deteriorates. In this case, services cannot be processed in a timely manner. Even worse, the malicious packets will cause a system breakdown.
An MPAC policy matches packets to be sent to the CPU and discards undesired packets. The main purpose of MPAC is to protect TCP/IP-based control plane against Denial of Service (DoS) attacks. For example, when an attacker continuously sends packets to a network device by simulating a routing protocol, the device is overloaded by the attack packets, causing a high CPU usage. An MPAC policy can match the packets to be sent to the CPU against certain rules and discard undesired packets.