User manual
52
ADVANCED FUNCTIONS
“http://www.blocked-site.com” or “http://11.22.33.44”), or a keyword contained in
a URL (like “pornography,” “sex,” “banner advertisement,” etc).
Add — Click to add the URL/keyword to the URL/Keyword Filtering Table.
Reset — Click to remove all entries in the “URL/Keyword” text eld.
Current URL Blocking Table — All existing URL/keywords in the ltering table.
Delete — Select a URL/keyword by checking the “Select” box of the entry, then
clicking “Delete.”
Delete All — Click to delete all existing URL/keyword entries.
3.3.4 DoS Attack Prevention
A denial-of-service (DoS) attack is an attempt to make a computer resource
unavailable to its intended users. DoS attacks generally consist of the concerted,
malevolent efforts of a person or persons to prevent an Internet site or service from
functioning efciently or at all, temporarily or indenitely. One common method of
attack involves saturating the target (victim) machine, in this case the router, with
external communications requests, such that it cannot respond to legitimate trafc
or responds so slowly as to be rendered effectively unavailable.
This router has a built-in DoS attack prevention mechanism to prevent DoS attacks
from succeeding. Activating all options is recommended.
Ping of Death — Ping of Death is a special
packet, and it will cause certain computers
to stop responding. Check this box and the
router will lter out this kind of packet.
Discard Ping From WAN — Ping is a common
and useful tool for knowing the connection
status of a specied remote network device,
but some malicious intruder could try to ll
your network bandwidth with a lot of PING
request data packets to make your Internet
connection become very slow — even
unusable. Check this box and the router will
ignore all inbound PING requests. NOTE:
Unfortunately, when you activate this function, you will not be able to ping your
own router from the Internet, either.
Port Scan — An intruder could try to use a port scanner to determine how many
ports of your Internet IP address are open, through which they can collect a lot
of valuable information. Check this box and the router will block all trafc that’s
involved in trying to scan your Internet IP address.
Sync Flood — Another kind of attack, this one uses a lot of fake connection requests
to consume the memory of your server, rendering it unusable. Check this box