1. Home
    2. /
  2. Manuals
    3. /
  3. Zyxel
    4. /
  4. NBG-418N v2
    5. /
  5. 23
Page 111 / 237 Scroll up to view Page 106 - 110
Chapter 10 Network Address Translation
NBG-418N v2 User’s Guide
111
10.6.2
NAT 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 79
Multiple Servers Behind NAT Example
10.6.3
Trigger Port Forwarding
Some services use a dedicated range of ports on the client side and a dedicated range of ports on
the server side. With regular port forwarding you set a forwarding port in NAT to forward a service
(coming in from the server on the WAN) to the IP address of a computer on the client side (LAN).
The problem is that port forwarding only forwards a service to a single LAN IP address. In order to
use the same service on a different LAN computer, you have to manually replace the LAN
computer's IP address in the forwarding port with another LAN computer's IP address.
Trigger port forwarding solves this problem by allowing computers on the LAN to dynamically take
turns using the service. The NBG-418N v2 records the IP address of a LAN computer that sends
traffic to the WAN to request a service with a specific port number and protocol (a "trigger" port).
When the NBG-418N v2's WAN port receives a response with a specific port number and protocol
("incoming" port), the NBG-418N v2 forwards the traffic to the LAN IP address of the computer that
sent the request. After that computer’s connection for that service closes, another computer on the
LAN can use the service in the same manner. This way you do not need to configure a new IP
address each time you want a different LAN computer to use the application.
10.6.4
Trigger Port Forwarding Example
The following is an example of trigger port forwarding.
Page 112 / 237
Chapter 10 Network Address Translation
NBG-418N v2 User’s Guide
112
Figure 80
Trigger Port Forwarding Process: Example
1
Jane requests a file from the Real Audio server (port 7070).
2
Port 7070 is a “trigger” port and causes the NBG-418N v2 to record Jane’s computer IP address.
The NBG-418N v2 associates Jane's computer IP address with the "incoming" port range of 6970-
7170.
3
The Real Audio server responds using a port number ranging between 6970-7170.
4
The NBG-418N v2 forwards the traffic to Jane’s computer IP address.
5
Only Jane can connect to the Real Audio server until the connection is closed or times out. The
NBG-418N v2 times out in three minutes with UDP (User Datagram Protocol), or two hours with
TCP/IP (Transfer Control Protocol/Internet Protocol).
10.6.5
Two Points To Remember About Trigger Ports
1
Trigger events only happen on data that is coming from inside the NBG-418N v2 and going to the
outside.
2
If an application needs a continuous data stream, that port (range) will be tied up so that another
computer on the LAN can’t trigger it.
Jane’s computer
Real Audio Server
Port 7070
Page 113 / 237
NBG-418N v2 User’s Guide
113
C
HAPTER
11
Dynamic DNS
11.1
Overview
Dynamic Domain Name Service (DDNS) services let you use a fixed domain name with a dynamic
IP address. Users can always use the same domain name instead of a different dynamic IP address
that changes each time to connect to the NBG-418N v2 or a server in your network.
Note: The NBG-418N v2 must have a public global IP address and you should have your
registered DDNS account information on hand.
11.2
Dynamic DNS Screen
To configure your NBG-418N v2’s DDNS, click
Network > DDNS
.
Figure 81
Network > DDNS
The following table describes the labels in this screen.
Table 51
Network > DDNS
LABEL
DESCRIPTION
Enable
Dynamic DNS
Click the
Enable Dynamic DNS
check box to enable DDNS.
Service
Provider
Select the name of your DDNS Service provider from the drop-down list.
Host Name
The Host name is the domain name that the DDNS service will map to your dynamic global
IP address. Type the host name fully qualified, for example, ‘yourhost.mydomain.net’. You
can specify up to two host names in the field separated by a comma (",").
User Name
Type the User name that you used when you registered with the DDNS service.
Password
Type the Password associated with the DDNS user name.
Apply
Click
Apply
to save your changes back to the NBG-418N v2.
Reset
Click
Reset
to begin configuring this screen afresh.
Page 114 / 237
Chapter 11 Dynamic DNS
NBG-418N v2 User’s Guide
114
Dynamic DDNS Table
Select
Click the
Select
check box to select the DDNS entry to modify the settings.
Dynamic DNS
This field displays whether the DDNS is
Enabled
or
Disabled
.
Service
Provider
This field displays the
Service provider
name of the DDNS.
Host Name
This field displays the host name that is associated with the DDNS.
User Name
This field displays the user name that is associated with the DDNS.
Table 51
Network > DDNS
LABEL
DESCRIPTION
Page 115 / 237
NBG-418N v2 User’s Guide
115
C
HAPTER
12
Static Route
12.1
Overview
This chapter shows you how to configure static routes for your NBG-418N v2.
The NBG-418N v2 usually uses the default gateway to route outbound traffic from computers on
the LAN to the Internet. To have the NBG-418N v2 send data to devices not reachable through the
default gateway, use static routes.
For example, the next figure shows a computer (
A
) connected to the NBG-418N v2’s LAN interface.
The NBG-418N v2 routes most traffic from
A
to the Internet through the NBG-418N v2’s default
gateway (
R1
). You create one static route to connect to services offered by your ISP behind router
R2
. You create another static route to communicate with a separate network behind a router
R3
connected to the LAN.
Figure 82
Example of Static Routing Topology
12.2
IP Static Route Screen
Click
Network > Static Route
to open the
Static Route
screen.
WAN
R1
R2
A
R3
LAN

Rate

4 / 5 based on 1 vote.

Popular Zyxel Models

Famous Router IPs
Famous Router Companies
Bookmark Our Site

Press Ctrl + D to add this site to your favorites!

Share
Top