Cisco 300 Series Administration Manual page 402

Security
Denial of Service Prevention
STEP 4
STEP 1
STEP 2
STEP 3
STEP 4
STEP 1
STEP 2
STEP 3
Cisco Small Business 200, 300 and 500 Series Managed Switch Administration Guide (Internal Version)
Click Apply. The SYN rate protection is defined, and the Running Configuration is
updated.
ICMP Filtering
The ICMP Filtering page enables the blocking of ICMP packets from certain
sources. This can reduce the load on the network in case of an ICMP attack.
To define ICMP filtering:
Click Security > Denial of Service Prevention > ICMP Filtering.
Click Add.
Enter the parameters.
• Interface—Select the interface on which the ICMP filtering is being defined.
• IP Address—Enter the IPv4 address for which the ICMP packet filtering is
activated or select All Addresses to block ICMP packets from all source
addresses. If you enter the IP address, enter either the mask or prefix length.
• Network Mask—Select the format for the subnet mask for the source IP
address, and enter a value in one of the field:
- Mask—Select the subnet to which the source IP address belongs and
enter the subnet mask in dotted decimal format.
- Prefix Length—Select the Prefix Length and enter the number of bits that
comprise the source IP address prefix.
Click Apply. The ICMP filtering is defined, and the Running Configuration is
updated.
IP Fragmented Filtering
The IP Fragmented page enables blocking fragmented IP packets.
To configure fragmented IP blocking:
Click Security > Denial of Service Prevention > IP Fragments Filtering.
Click Add.
Enter the parameters.
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