Chapter 11 Network Address Translation (NAT)
XMG3512-B10A User’s Guide
156
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 XMG 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 XMG's WAN port
receives a response with a specific port number and protocol ("open" port), the XMG 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.
For example:
Figure 81
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 XMG to record Jane’s computer IP address. The XMG
associates Jane's computer IP address with the "open" port range of 6970-7170.
3
The Real Audio server responds using a port number ranging between 6970-7170.
4
The XMG 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 XMG
times out in three minutes with UDP (User Datagram Protocol) or two hours with TCP/IP (Transfer Control
Protocol/Internet Protocol).
Click
Network Setting > NAT > Port Triggering
to open the following screen. Use this screen to view your
XMG’s trigger port settings.
Figure 82
Network Setting > NAT > Port Triggering
Содержание XMG3512-B10A
Страница 14: ...14 PART I User s Guide ...
Страница 23: ...Chapter 1 Introducing the XMG XMG3512 B10A User s Guide 23 Figure 8 Wall Mounting Example ...
Страница 33: ...Chapter 3 Quick Start XMG3512 B10A User s Guide 33 Figure 16 Quick Start Result Summary ...
Страница 56: ...56 PART II Technical Reference ...
Страница 139: ...Chapter 10 Quality of Service QoS XMG3512 B10A User s Guide 139 Figure 71 Classification Setup Add Edit ...
Страница 249: ...249 PART III Appendices Appendices contain general information Some information may not apply to your device ...
Страница 279: ...Appendix D Legal Information XMG3512 B10A User s Guide 279 Environmental Product Declaration ...