Firewall Security

F

 

Level Services Table

 

The following information is related to the Firewall options (High, Medium, and Low) section in the “Advanced Setup” chapter of this manual (see page 56). The types of services and their respective ports are listed in the two right-hand col- umns: the “In” column details whether a particular service can be accessed by a user outside of the network; and the “Out” column details 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., to host 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.

High Security Level

Service

Port

In

Out

http

80

no

yes

dns

53

no

yes

ftp

21

no

no

telnet

23

no

no

smtp

25

yes

yes

pop3

110

yes

yes

nntp

119

no

no

real audio/video

7070

no

no

icmp

n/a

no

yes

H.323

1720

no

no

T.120

1503

no

no

SSH

22

no

no

imap

163

yes

yes

https

443

yes

yes

secure imap

983

yes

yes

secur pop3

885

yes

yes

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Image 120
Actiontec electronic GT701WG user manual Firewall Security Level Services Table, High Security Level