Denial of Service Protection
D-Link Unified Wired and Wireless Access System
Oct. 2015 Page 89
D-Link UWS User Manual
• If you change any of the DoS settings, click Submit to apply the changes to the switch. To preserve the
changes across a switch reboot, you must perform a save.
Table 18: Denial of Service Configuration Fields
Field Description
Denial of Service First
Fragment
Enable or disable this option by selecting the corresponding line on the
pulldown entry field. Enabling First Fragment DoS prevention causes the
switch to drop packets that have a TCP header smaller then the configured
Min TCP Hdr Size. The factory default is disabled.
Denial of Service Min TCP Hdr
Size
Specify the Min TCP Hdr Size allowed. If First Fragment DoS prevention is
enabled, the switch will drop packets that have a TCP header smaller then this
configured Min TCP Hdr Size. The factory default is disabled.
Denial of Service ICMP Enable or disable this option by selecting the corresponding line on the
pulldown entry field. Enabling ICMP DoS prevention causes the switch to drop
ICMP packets that have a type set to ECHO_REQ (ping) and a size greater than
the configured ICMP Pkt Size. The factory default is disabled.
Denial of Service Max ICMP
Size
Specify the Max ICMP Pkt Size allowed. If ICMP DoS prevention is enabled, the
switch will drop ICMP ping packets that have a size greater than this
configured Max ICMP Pkt Size. The factory default is disabled.
Denial of Service L4 Port Enable or disable this option by selecting the corresponding line on the
pulldown entry field. Enabling L4 Port DoS prevention causes the switch to
drop packets that have TCP/UDP source port equal to TCP/UDP destination
port. The factory default is disabled.
Denial of Service SIP=DIP Enable or disable this option by selecting the corresponding line on the
pulldown entry field. Enabling SIP=DIP DoS prevention causes the switch to
drop packets that have a source IP address equal to the destination IP address.
The factory default is disabled.
Denial of Service TCP Flag Enable or disable this option by selecting the corresponding line on the
pulldown entry field. Enabling TCP Flag DoS prevention causes the switch to
drop packets that have TCP flag SYN set and TCP source port less than 1024 or
TCP control flags set to 0 and TCP sequence number set to 0 or TCP flags FIN,
URG, and PSH set and TCP sequence number set to 0 or both TCP flags SYN and
FIN set. The factory default is disabled.
Denial of Service TCP
Fragment
Enable or disable this option by selecting the corresponding line on the
pulldown entry field. Enabling TCP Fragment DoS prevention causes the
switch to drop packets that have an IP fragment offset equal to 1. The factory
default is disabled.