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The following table describes the labels in this screen.
Table 42
NAT > Port Triggering > Add
LABEL
DESCRIPTION
Active
Clear the check box to disable the rule. Select the check box to enable it.
This field is not editable if you are configuring a
User Define
rule.
Service
Name
Enter a name to identify this rule. This field is read-only if you click the
Edit
icon in the
Trigger
Port
screen.
WAN
Interface
Select a WAN interface for which you want to configure port triggering rules.
Trigger
Start Port
The trigger port is a port (or a range of ports) that causes (or triggers) the
Device to record the IP address of the LAN computer that sent the traffic to
a server on the WAN.
Type a port number or the starting port number in a range of port numbers.
Trigger End
Port
Type a port number or the ending port number in a range of port numbers.
Trigger
Protocol
Select the IP protocol from
TCP
,
UDP
, or
TCP/UDP
.
Open Start
Port
The open port is a port (or a range of ports) that a server on the WAN uses
when it sends out a particular service. The Device forwards the traffic with
this port (or range of ports) to the client computer on the LAN that
requested the service.
Type a port number or the starting port number in a range of port numbers.
Open End
Port
Type a port number or the ending port number in a range of port numbers.
Open
Protocol
Select the IP protocol from
TCP
,
UDP
, or
TCP/UDP
.
Back
Click
Back
to return to the previous screen.
Apply
Click
Apply
to save your changes to the Device.
Cancel
Click
Cancel
to begin configuring this screen afresh.
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8.5
The DMZ Host Screen
In addition to the servers for specified services, NAT supports a default server IP
address. A default server receives packets from ports that are not specified in the
NAT Port Forwarding Setup
screen.
Figure 75
NAT > DMZ Host
The following table describes the fields in this screen.
8.6
The ALG Screen
Some NAT routers may include a SIP Application Layer Gateway (ALG). A SIP ALG
allows SIP calls to pass through NAT by examining and translating IP addresses
embedded in the data stream. The SIP ALG translates the Device’s private IP
address inside the SIP data stream to a public IP address. You do not need to use
STUN or an outbound proxy if you enable the SIP ALG.
Table 43
NAT > DMZ Host
LABEL
DESCRIPTION
Default Server
Enter the IP address of the default server which receives packets from
ports that are not specified in the
NAT Port Forwarding
screen.
Note: If you do not assign a
Default Server
, the Device discards all
packets received for ports that are not specified in the
NAT
Port Forwarding
screen.
Apply
Click
Apply
to save your changes back to the Device.
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Use this screen to enable or disable the SIP (VoIP) ALG in the Device. To access
this screen, click
NAT > ALG
.
Figure 76
NAT > ALG
Each field is described in the following table.
8.7
Technical Reference
The following section contains additional technical information about the Device
features described in this chapter.
Port Forwarding: Services and Port Numbers
The most often used port numbers are shown in the following table. Please refer
to RFC 1700 for further information about port numbers. Please also refer to the
Supporting CD for more examples and details on port forwarding and NAT.
Table 44
NAT > ALG
LABEL
DESCRIPTION
Active SIP ALG
Select this check box to allow SIP sessions to pass through the Device.
SIP is a signaling protocol used in VoIP (Voice over IP), the sending of
voice signals over Internet Protocol.
Apply
Click
Apply
to save your customized settings.
Table 45
Services and Port Numbers
SERVICES
PORT NUMBER
ECHO
7
FTP (File Transfer Protocol)
21
SMTP (Simple Mail Transfer Protocol)
25
DNS (Domain Name System)
53
Finger
79
HTTP (Hyper Text Transfer protocol or WWW, Web)
80
POP3 (Post Office Protocol)
110
NNTP (Network News Transport Protocol)
119
SNMP (Simple Network Management Protocol)
161
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Port Forwarding Example
Let's say you want to assign ports 21-25 to one FTP, Telnet and SMTP server (
A
in
the example), port 80 to another (
B
in the example) and assign a default server IP
address of 192.168.1.35 to a third (
C
in the example). You assign the LAN IP
addresses and the ISP assigns the WAN IP address. The NAT network appears as a
single host on the Internet.
Figure 77
Multiple Servers Behind NAT Example
SNMP trap
162
PPTP (Point-to-Point Tunneling Protocol)
1723
Table 45
Services and Port Numbers
SERVICES
PORT NUMBER
Internet
D=192.168.1.36
192.168.1.1
IP address assigned by ISP
A=192.168.1.33
B=192.168.1.34
C=192.168.1.35
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C
HAPTER
9
MAC Filter
This chapter discusses MAC address filtering.
9.1
Overview
MAC filtering means sifting traffic going through the Device based on the source
and/or destination MAC addresses.
9.1.1
What You Can Do in this Chapter
The
MAC Filter
screen lets you view and configure the MAC filtering rules (
Section
9.2 on page 156
).
19216811.live