Westermo MRD-3x0 - Manual (Page 70)

70 6623-3201
5.3.1 Enabling the Denial of Service filters
The Filter Description table provides a number of DOS filters,
as shown in Figure 54. The filters can be applied to packets
received from the LAN port, the wireless port (WLS), and
from any VPN tunnel by checking the boxes in the appropriate
column.
Figure 54: Firewall DoS filter options.
The function of each filter is described below:
Rate limit TCP SYN packets
This will limit the number of new TCP connection requests
(SYN packets) allowed from the given interface. The rate will
be limited to 5 per second.
Drop invalid TCP flag combinations
Some DOS attacks will send packets that present an invalid
combination of TCP flags which may cause problems for some
operating systems. The filter will drop packets with invalid
combinations received on the given interface.
Rate limit ICMP requests
This will limit the number of ICMP requests (for example, ping
requests) allowed from the given interface. The rate will be
limited to 5 per second.
Accept limited ICMP types
The types of ICMP packets that are accepted will be limited
to types 0, 3, 8 and 11.