Chapter 2: Configuring System Information | 43
GS716Tv2 and GS724Tv3 Software Administration Manual
to drop packets that have a TCP header smaller than the configured Min TCP Hdr
Size. The factory default is Disable.
• 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 than this configured Min TCP Hdr Size. The factory default is 20
bytes.
• Denial of Service TCP Fragment. Enable or disable this option by selecting the
appropriate radio button. Enabling TCP Fragment DoS prevention causes the switch
to drop packets that have an IP fragment offset equal to 1. The factory default is
Disable.
• Denial of Service TCP Flag. Enable or disable this option by selecting the
appropriate radio button. 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 Disable.
• Denial of Service L4 Port. Enable or disable this option by selecting the appropriate
radio button. 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
Disable.
• Denial of Service ICMP. Enable or disable this option by selecting the appropriate
radio button. 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 packet size. The factory default is Disable.
• Denial of Service Max ICMP Size. Specify the Max ICMP packet size allowed. If
ICMP DoS prevention is enabled, the switch will drop ICMP ping packets that have a
size greater then this configured Max ICMP packet size. The factory default is
Disable.
2. If you change any of the DoS settings, click Apply to apply the changes to the switch.
3. Click Cancel to cancel the configuration on the screen and reset the data on the screen to
the latest value of the switch.
DNS
You can use these pages to configure information about DNS servers the network uses and
how the switch operates as a DNS client.

DNS Configuration

Use this page to configure global DNS settings and DNS server information.
To access this page, click System Management DNS DNS Configuration.