Security
87
A750 Wireless Dual Band Gigabit Router JR6150
Port FIltering to Block Services
Services are functions performed by server computers at the request of client computers. For
example, web servers serve web pages, time servers serve time and date information, and
game hosts serve data about players’ moves. When a computer on the Internet sends a
request for service to a server computer, the requested service gets identified by a service or
port number. This number appears as the destination port number in the transmitted IP
packets. For example, a packet that is sent with the destination port number 80 is an HTTP
(web server) request.
The service numbers for many common protocols are defined by the Internet Engineering
Task Force (IETF at
http://www.ietf.org/
) and published in RFC1700, “Assigned Numbers.”
The authors of other applications typically choose service numbers for those applications
from the range 1024–65535. Although the router already holds a list of many service port
numbers, you are not limited to these choices. You can often find port number information by
contacting the publisher of the application, by asking user groups or newsgroups, or by
searching.
You can add and block specific Internet services by computers on your network. This process
is called service blocking or port filtering. To add a service for blocking, first determine which
port number or range of numbers the application uses.
To block services:
1.
Log in to the router.
For more information, see
Use NETGEAR genie after Installation
on page
17.
2.
Select
ADVANCED > Security > Block Services
.
3.
Select either the
Per Schedule
radio button or the
Always
radio button.
4.
If you selected
Per Schedule
, specify a time period in the Schedule screen.
For more information, see
Schedule Blocking
on page
88.
