GEN:SID 1:399
Message ICMP Destination Unreachable Host Unreachable
Summary This event is generated when An ICMP Host Unreachable datagram is detected on the network.  
Impact Routers will generate this message when the route to the destination host on a directly connected network is not available.  This occurs when no ARP response is received from the destination network.
Detailed Information This rule generates informational events about the network.  Large numbers of these messages on the network could indication routing problems, faulty routing devices, or improperly configured hosts.
Affected Systems  
Attack Scenarios None Known
Ease of Attack Numerous tools and scripts can generate these types of ICMP datagrams.
Corrective Action This rule detects informational network information, no corrective action is necessary.
Additional References None