CBV704EW Series Cable Modem
User’s Manual
18
example, you could block access to worldwide web browsing (HTTP port 80)
but still allow email service (SMTP port 25 and POP3 port 110).
To enable port filtering, enter the
Start port
and
End port
for each range.
Then select its protocol form the drop-down list and check the
Enable
box,
and click
Apply
button. To block only one port, set both Start and End ports
the same.
5.1.7 Forwarding
For communications between LAN and WAN, the CBV704EW normally only
allows you to originate an IP connection with a PC on the WAN; it will ignore
attempts of the WAN PC to originate a connection onto your PC. This protects
you from malicious attacks from outsiders. However, sometimes you may wish
for anyone outside to be able to originate a connection to a particular PC on
your LAN if the destination port (application) matches one you specify.
The Forwarding page allows you to specify up to 10 rules.
Using the Port Forwarding page, you can provide local services (web servers,
FTP servers, mail servers, etc) for people on the Internet or play Internet
games. A table of commonly used port numbers is also provided.