Cisco 500 series Administration Manual page 334

Configuring Security
Denial of Service Prevention
STEP 5
STEP 1
STEP 2
STEP 3
Cisco 500 Series Stackable Managed Switch Administration Guide
From reserved List
-
list.
New IP Address
-
• Mask—Enter the mask of the IP address to define a range of IP addresses to
reject. The values are:
Network Mask
-
Prefix Length
-
addresses for which Denial of Service prevention is enabled.
Click Apply. The Martian addresses are written to the Running Configuration file.
Define SYN Filtering
SYN Filtering
The page enables filtering TCP packets that contain a SYN flag, and
are destined for one or more ports.
To define a SYN filter:
Click Security > Denial of Service Prevention > SYN Filtering. The SYN Filtering
page is displayed.
Click Add. The Add SYN Filtering page is displayed.
Enter the parameters.
• Interface—Select the interface on which the filter is defined.
• IPv4 Address—Enter the IP address for which the filter is defined, or select
All Addresses.
• Network Mask—Enter the network mask for which the filter is enabled in IP
address format.
• TCP Port—Select the destination TCP port being filtered:
- Known Ports—Select a port from the list.
- User Defined—Enter a port number.
- All Ports—Select to indicate that all ports are filtered.
—Select a well-known IP address from the reserved
—Enter an IP address.
—Network mask in dotted decimal format.
—Enter the prefix of the IP address to define the range of IP
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