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ARP Spoof Preprocessor

The ARP spoof preprocessor decodes ARP packets and detects ARP attacks, unicast ARP requests, and inconsistent Ethernet to IP mapping.

When no arguments are specified to arpspoof, the preprocessor inspects Ethernet addresses and the addresses in the ARP packets. When inconsistency occurs, an alert with GID 112 and SID 2 or 3 is generated.

When "-unicast" is specified as the argument of arpspoof, the preprocessor checks for unicast ARP requests. An alert with GID 112 and SID 1 will be generated if a unicast ARP request is detected.

Specify a pair of IP and hardware address as the argument to arpspoof_detect_host. The host with the IP address should be on the same layer 2 segment as Snort is. Specify one host IP MAC combo per line. The preprocessor will use this list when detecting ARP cache overwrite attacks. Alert SID 4 is used in this case.


Eugene Misnik 2013-05-08