Draytek Vigor2500V Manual page 74

Firewall
A.4 Warning Message
All the warning messages will be sent to syslog client after you enable
the syslog function. The administrator can go to System
Maintenance >> Syslog Setup / Mail Alert to setup the syslog client.
Thus, the administrator can look at the warning messages from DoS
Defense functionality through the DrayTek Sylsog daemon. The format
for this kind of the warning messages is similar to those in Firewall
except for the preamble keyword "DoS", followed by a name to
indicate what kind of attacks is detected.
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