US Patent 7940757 Systems and methods for access port ICMP analysis

Systems and methods perform analysis of ICMP packets received at a network device port to determine if the ICMP packet is valid and thus should be forwarded. One aspect of the systems and methods includes configuring a port to be a trusted port in which any type of ICMP message may be considered valid. For untrusted ports, the system analyzes the ICMP packet to determine if the packet is one that should be received on an untrusted port. A further aspect of the systems and methods includes analyzing the ICMP packet data to determine if packet addresses have been spoofed or altered.