Netgear C6250 Ac1600 Wifi Cable Modem Router User Manual

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4. 
Click the  OK button.
The BASIC Home page displays.
5.  Select  ADV
 ANCED > Advanced Setup > Port Forwarding / Port Triggering.
The following figure shows two port forwarding rules.
6.  Make sure that the  Port Forwarding radio button is selected.
7.  In the table, select the radio button next to the service or application\
 name.
8.  Click the  Delete Service button.
The rule is removed from the table.
Application Example: Make a Local Web Server Public
If you host a web server on your local network, you can use port forward\
ing to allow web 
requests from anyone on the Internet to reach your web server. 
To make a local web server public:
1.  Assign your web server either a fixed IP address or a dynamic IP address\
 using DHCP 
address reservation. 
In this example, your modem router always gives your web server an IP ad\
dress of 
192.168.1.55. 
2.  On the Port Forwarding / Port 
 Triggering page, configure the modem router to forward the 
HTTP service to the local address of your web server at  192.168.1.55. 
HTTP (port 80) is the standard protocol for web servers. 
						

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3. (Optional) Register a host name with a Dynamic DNS service, and specify that name on the 
Dynamic DNS page of the modem router. 
Dynamic DNS makes it much easier to access a server from the Internet because you 
can enter the name in the Internet browser. Otherwise, you must know the IP address 
that the ISP assigned, which typically changes.
How the Modem Router Implements the Port Forwarding Rule
The following sequence shows the effects of a port forwarding rule:
1. When you enter the URL www.example.com in your browser, the browser sends a web 
page request message with the following destination information: 
•Destination address. The IP address of www.example.com, which is the address of 
your modem router.
•Destination port number. 80, which is the standard port number for a web server 
process.
2. The modem router receives the message and finds your port forwarding rule for incoming 
port 80 traffic. 
3. The modem router changes the destination in the message to IP address 192.168.1.123 
and sends the message to that computer.
4. Your web server at IP address 192.168.1.123 receives the request and sends a reply 
message to your modem router.
5. Your modem router performs Network Address Translation (NAT) on the source IP address 
and sends the reply through the Internet to the computer or WiFi device that sent the web 
page request. 
Manage Port Triggering for Services, Applications, and 
Games
Port triggering is a dynamic extension of port forwarding that is useful in these cases:
•An application must use port forwarding to more than one local computer (but not 
simultaneously).
•An application must open incoming ports that are different from the outgoing port.
With port triggering, the modem router monitors traffic to the Internet from an outbound 
“trigger” port that you specify. For outbound traffic from that port, the modem router saves the 
IP address of the computer that sent the traffic. The modem router temporarily opens the 
incoming port or ports that you specify in your rule and forwards that incoming traffic to that 
destination.
Port forwarding creates a static mapping of a port number or range of ports to a single local 
computer. Port triggering can dynamically open ports to any computer when needed and 
close the ports when they are no longer needed. 
						

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Note:
If you use applications such as multiplayer gaming, peer-to-peer 
connections, real-time communications such as instant messaging, or 
remote assistance, enable Universal Plug and Play (UPnP). See 
Manage Universal Plug and Play on page  92.
Add a Port Triggering Rule
The modem router does not provide default services and applications for \
port triggering rules. 
You must define a custom service or application for each port triggering \
rule.
To add a port triggering rule:
1. Launch an Internet browser from a computer or WiFi device that is connec\
ted to the 
network.
2.  T
ype  http://www.routerlogin.net .
A login window opens.
3.  T
ype  admin for the user name and type your password.
If you did not yet personalize your password, type  password for the password.
4.  Click the  OK button.
The BASIC Home page displays.
5.  Select  ADV
 ANCED > Advanced Setup > Port Forwarding / Port Triggering. 
The Port Forwarding / Port Triggering page displays.
6.  Select the Port T
 riggering radio button.
7. Click the  Add Service button. 
						

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8. 
Specify a new port triggering rule with a custom service or application \
as described in the 
following table.
FieldDescription
Service Name Enter the name of the custom service or application.
Service User From the Service User menu, select  Any, or select  Single address and enter 
the IP address of one computer:
•  Any . 
This is the default setting and allows any computer on the Internet to 
use this service. 
•  Single address . Restricts the service to a particular computer
 . 
Service Type Select the protocol (TCP or UDP) that is associated with the service or 
application.
Triggering Starting Port Enter the number of the outbound traffic start port that must open the inbound 
ports. 
Triggering Ending Port Enter the number of the outbound traffic end port that must open the inbound 
ports. 
Inbound Connection
Starting Port Enter the start port number for the inbound connection.
Ending Port Enter the end port number for the inbound connection.
9. Click the  Apply button.
Your settings are saved. The rule is added to the Port Triggering Portmap Table on the  Port Forwarding / Port 
 Triggering page and is enabled. 
						

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Change a Port Triggering Rule
You can change an existing port triggering rule.
To change a port triggering rule:
1. 
Launch an Internet browser from a computer or WiFi device that is connec\
ted to the 
network.
2.  T
ype  http://www.routerlogin.net .
A login window opens.
3.  T
ype  admin for the user name and type your password.
If you did not yet personalize your password, type  password for the password.
4.  Click the  OK button.
The BASIC Home page displays.
5.  Select  ADV
 ANCED > Advanced Setup > Port Forwarding / Port Triggering.
The Port Forwarding / Port Triggering page displays.
6.  Select the Port T
 riggering radio button.
The following figure shows two port triggering rules.
7.  In the Port Triggering Portmap Table, select the radio button next to the service or 
application name.
8.  Click the  Edit Service button.
The Port Triggering - Services page displays.
9.  Change the settings. 
						

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For more information about the settings, see Add a Port Triggering Rule on page
 173.
10.  Click the  Apply button.
Your settings are saved. The changed rule displays in the Port Triggering Portmap Table  on the Port Forwarding / Port 
 Triggering page.
Disable or Remove a Port Triggering Rule
You can disable or remove a port triggering rule that you no longer need.\
To disable or remove a port triggering rule:
1. Launch an Internet browser from a computer or WiFi device that is connec\
ted to the 
network.
2.  T
ype  http://www.routerlogin.net .
A login window opens.
3.  T
ype  admin for the user name and type your password.
If you did not yet personalize your password, type password for the password.
4.  Click the  OK button.
The BASIC Home page displays.
5.  Select  ADV
 ANCED > Advanced Setup > Port Forwarding / Port Triggering.
The Port Forwarding / Port Triggering page displays.
6.  Select the  Port T
 riggering radio button.
The following figure shows two port triggering rules. 
						

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7. To disable the rule, do the following:
a.In the Enable column of the Port Triggering Portmap Table, clear the check box next 
to the service or application name.
b. Click the Apply button.
Your settings are saved.
8. To remove the rule entirely, do the following:
a.In the Port Triggering Portmap Table, select the radio button next to the service or 
application name.
b. Click the Delete Service button.
The rule is removed from the Port Triggering Portmap Table.
Specify the Time-Out Period for Port Triggering
The time-out period for port triggering controls how long the inbound ports stay open when 
the modem router detects no activity. A time-out period is required because the modem 
router cannot detect when the service or application terminates. 
To specify the time-out for port triggering: 
1. Launch an Internet browser from a computer or WiFi device that is connected to the 
network.
2. Type http://www.routerlogin.net.
A login window opens.
3. Type admin for the user name and type your password.
If you did not yet personalize your password, type password for the password.
4. Click the OK button.
The BASIC Home page displays.
5. Select ADVANCED > Advanced Setup > Port Forwarding / Port Triggering.
The Port Forwarding / Port Triggering page displays.
6. Select the Port Triggering radio button.
The port triggering settings display.
7. In the Port Triggering Time-out field, enter a value up to 9999 minutes. 
The default setting is 10 minutes. 
8. Click the Apply button.
Your settings are saved. 
						

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Disable Port Triggering
By default, port triggering is enabled. You can disable port triggering temporarily without 
removing any port triggering rules.
To disable port triggering:
1. Launch an Internet browser from a computer or WiFi device that is connected to the 
network.
2. Type http://www.routerlogin.net.
A login window opens.
3. Type admin for the user name and type your password.
If you did not yet personalize your password, type password for the password.
4. Click the OK button.
The BASIC Home page displays.
5. Select ADVANCED > Advanced Setup > Port Forwarding / Port Triggering.
The Port Forwarding / Port Triggering page displays.
6. Select the Port Triggering radio button.
The port triggering settings display.
7. Select the Disable Port Triggering check box.
If this check box is selected, the modem router does not apply port triggering rules even if 
you specified them.
8. Click the Apply button.
Your settings are saved.
Application Example: Port Triggering for Internet Relay Chat 
Some application servers, such as FTP and IRC servers, send replies to multiple port 
numbers. Using port triggering, you can tell the modem router to open more incoming ports 
when a particular outgoing port starts 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 modem router, “When you initiate a session with destination port 6667, you must also 
allow incoming traffic on port 113 to reach the originating computer.”  
						

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The following sequence shows the effects of this port triggering rule:
1. You open an IRC client program to start 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 modem router.
3. Your modem router creates an entry in its internal session table describing this 
communication session between your computer and the IRC server. Your modem 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 observing the destination port number of 6667, your 
modem router creates another session entry to send any incoming port 113 traffic to your 
computer.
5. The IRC server sends a return message to your modem router using the NAT-assigned 
source port (for example, port 33333) as the destination port and the IRC server also sends 
an “identify” message to your modem router with destination port 113.
6. When your modem router receives the incoming message to destination port 33333, it 
checks its session table to see if a session is active for port number 33333. Finding an 
active session, the modem router restores the original address information replaced by NAT 
and sends this reply message to your computer.
7. When your modem router receives the incoming message to destination port 113, it checks 
its session table and finds an active session for port 113 associated with your computer. The 
modem router replaces the message’s destination IP address with your computer’s IP 
address and forwards the message to your computer.
8. When you finish your chat session, your modem router eventually senses a period of 
inactivity in the communications. The modem router then removes the session information 
from its session table, and incoming traffic is no longer accepted on port numbers 33333 or 
113. 
						

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13
13.   Diagnostics and Troubleshooting
This chapter provides information to help you diagnose and solve problems that might occur with 
the modem router.
This chapter contains the following sections:
•Perform Diagnostics
•Quick Tips for Troubleshooting
•Troubleshoot with the LEDs
•You Cannot Log In to the Modem Router
•View and Manage the Event Log
•Troubleshoot the Internet Connection
•Changes Are Not Saved
•Troubleshoot the WiFi Connectivity
•TCP/IP Network Not Responding