519657
59
Zoom out
Zoom in
Previous page
1/112
Next page
Chapter 5: Fine-Tuning Your Network | 59
N150 Wireless Router User Manual
The Web server then sends this reply message to your router.
5. Upon receiving the incoming message, your router checks its session table to determine
whether there is an active session for port number 33333. Finding an active session, the
router then modifies the message, restoring the original address information replaced by
NAT. The message now contains the following address and port information:
The source address is the IP address of www.example.com.
The source port number is 80, the standard port number for a Web server process.
The destination address is your computer’s IP address.
The destination port number is 5678, the browser session that made the initial
request.
Your router then sends this reply message to your computer, which displays the Web
page from www.example.com.
6. When you finish your browser session, your router eventually senses a period of inactivity in
the communications. Your router then removes the session information from its session
table, and incoming traffic is no longer accepted on port number 33333.
How Port Triggering Changes the Communication Process
In the preceding example, requests are sent to a remote computer by your router from a
particular service port number, and replies from the remote computer to your router are
directed to that port number. If the remote server sends a reply back to a different port
number, your router will not recognize it and will discard it. However, some application
servers (such as FTP and IRC servers) send replies back to multiple port numbers. Using the
port triggering function of your router, you can tell the router to open additional incoming ports
when a particular outgoing port originates
a session.
An example is Internet Relay Chat (IRC). Your computer connects to an IRC server at
destination port 6667. The IRC server not only responds to your originating source port, but
also sends an “identify” message to your computer on port 113. Using port triggering, you can
tell the router, “When you initiate a session with destination port 6667, you must also allow
incoming traffic on port 113 to reach the originating computer.” Using steps similar to the
preceding example, the following sequence shows the effects of the port triggering rule you
have defined:
1. You open an IRC client program, beginning a chat session on your computer.
2. Your IRC client composes a request message to an IRC server using a destination port
number of 6667, the standard port number for an IRC server process. Your computer then
sends this request message to your router.
3. Your router creates an entry in its internal session table describing this communication
session between your computer and the IRC server. Your router stores the original
information, performs Network Address Translation (NAT) on the source address and port,
and sends this request message through the Internet to the IRC server.
4. Noting your port triggering rule, and having observed the destination port number of 6667,
your router creates an additional session entry to send any incoming port 113 traffic to your
computer.
59


Need help? Post your question in this forum.

Forumrules


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for Netgear WNR1000v3 at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of Netgear WNR1000v3 in the language / languages: English as an attachment in your email.

The manual is 4,92 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

Others manual(s) of Netgear WNR1000v3

Netgear WNR1000v3 Installation Guide - English - 2 pages

Netgear WNR1000v3 Installation Guide - German - 2 pages

Netgear WNR1000v3 Installation Guide - Dutch - 2 pages


The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info