Security level services table – Actiontec electronic GS204AD9-01 User Manual
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Security Level
Services Table
The following information is related to the Firewall options (High, Medium, and
Low) in the “Advanced Services” chapter of this manual (page 35). The types of
services and their respective ports are listed in the two right-hand columns; the
“In” column details if a particular service can be accessed by a user outside of the
network; and the “Out” column informs whether a computer on the Gateway’s
network can access a particular incoming service.
For example, in the “High Security Level” section, below, the http service uses port
80. Since “no” is listed in the In column, a user outside the Gateway’s network can-
not access a computer on the network via the http service; in this case, no comput-
ers on the network can be used as a Web server (i.e., hosting a Web site accessible
to outside users). However, since “yes” is listed in the Out column, all computers
on the Gateway’s network can access the Internet via the http port.
If Basic Security is selected in the “Firewall” screen, firewall filtering is based on the
basic NAT firewall.
☞
Note: The stateful packet inspection firewall is based on the
Globespan-Virata implementation and specification for release 8.2.
High Security Level
Service
Port
In
Out
http
80
no
yes
dns
53
no
yes
ftp
21
no
no
telnet
23
no
yes
smtp
25
no
yes
pop3
110
no
yes
nntp
119
no
no
real audio/video
7070
no
yes
icmp
n/a
no
yes
H.323
1720
no
no
T.120
1503
no
no
SSH
22
no
no
D