User manual
LinkMAX
 HSA300 User Manual
 104 
2.  Configure any of the following settings that display in the 
Firewall Global Information table: 
Field  Description 
Black List Status 
If you want the device to maintain and use a 
black list, click Enable. Click Disable if you do not 
want to maintain a list. 
Black List 
Period(min) 
Specifies the number of minutes that a 
computer's IP address will remain on the black 
list (i.e., all traffic originating from that computer 
will be blocked from passing through any 
interface on the ADSL/Ethernet router). For more 
information, see “Managing the Black List” on 
page 106. 
Attack Protection  Click the Enable radio button to use the built-in 
firewall protections that prevent the following 
common types of attacks: 
o  IP Spoofing: Sending packets over the WAN 
interface using an internal LAN IP address 
as the source address. 
o 
Tear Drop: Sending packets that contain 
overlapping fragments. 
o 
Smurf and Fraggle: Sending packets that 
use the WAN or LAN IP broadcast address 
as the source address. 
o 
Land Attack: Sending packets that use the 
same address as the source and 
destination address. 
o  Ping of Death: Illegal IP packet length. 
DoS Protection 
Click the Enable radio button to use the following 
denial of service protections: 
o 
SYN DoS 
o 
ICMP DoS 
o  Per-host DoS protection 
Max Half open 
TCP Connection 
Sets the percentage of concurrent IP sessions 
that can be in the half-open state. In ordinary 
TCP communication, packets are in the half-
open state only briefly as a connection is being 
initiated; the state changes to active when 
packets are being exchanged, or closed when 
the exchange is complete. TCP connections in 
the half-open state can use up the available IP 
sessions. 
If the percentage is exceeded, then the half-open 
sessions will be closed and replaced with new 
sessions as they are initiated. 
Max ICMP 
Connection 
Sets the percentage of concurrent IP sessions 
that can be used for ICMP messages. 
If the percentage is exceeded, then older ICMP 
IP sessions will be replaced by new sessions as 
the are initiated. 
Max Single Host 
Connection 
Sets the percentage of concurrent IP session 
that can originate from a single computer. This 
percentage should take into account the number 
of hosts on the LAN. 










