GEN:SID 1:487
Message ICMP Destination Unreachable Communication with Destination Network is Administratively Prohibited
Summary This event is generated when an ICMP destination unreachable
(Communication with Destination Host is Administratively Prohibited)
datagram is detected on the network.  
Impact This message is generated when a datagram failed to traverse the
network.  This could be an indication of routing or network problems.
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, so no corrective
action is necessary.
Additional References None.