ZyWALL 35 User's Guide
Figure 72 Smurf Attack
9.4.2.1 ICMP Vulnerability
ICMP is an error-reporting protocol that works in concert with IP. The following ICMP types
trigger an alert:
Table 55 ICMP Commands That Trigger Alerts
5
13
14
17
18
9.4.2.2 Illegal Commands (NetBIOS and SMTP)
The only legal NetBIOS commands are the following - all others are illegal.
Table 56 Legal NetBIOS Commands
MESSAGE:
REQUEST:
POSITIVE:
NEGATIVE:
RETARGET:
KEEPALIVE:
178
REDIRECT
TIMESTAMP_REQUEST
TIMESTAMP_REPLY
ADDRESS_MASK_REQUEST
ADDRESS_MASK_REPLY
Chapter 9 Firewalls