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[ScreenOS] What is a Land attack?



Article ID: KB5205 KB Last Updated: 28 Jan 2013Version: 4.0
This article provides information about the Land attack.
Information about the Land attack.


The Land attack combines the SYN attack with IP Spoofing. When a remote PC sends one or more SYN packets to a network with a spoofed IP address, the perception is that the host has sent a packet to itself and a denial of service condition is created, as the host is trying to respond to itself.  With the combination of the SYN proxy and the IP Spoof protection, the NetScreen device will block any attempts of this nature.

Note: the 'Land' attack protection that is currently implemented in ScreenOS will only drop SYN packets; in other words, an ACK packet with the same source and destination IP address or port will not be dropped by the firewall protection.

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