Netgear C3700 N600 Wifi Cable Modem Router User Manual

							Manage Your Network 81
 N600 WiFi Cable Modem Router Model C3700
To set up remote management:
1. 
Launch a web browser from a computer or wireless device that is connecte\
d to the 
network.
2.  T
ype  http://routerlogin.net  or http://192.168.0.1.
A login screen displays.
3.  Enter the modem router  user name and password.
The user name is  admin. 
 The default password is password. The user name and 
password are case-sensitive.
The BASIC Home screen displays.
4.  Select  ADV
 ANCED > Advanced Setup > Remote Management . 
5. Select the Turn Remote Management On  check box.
6.  Under 
Allow Remote Access By, specify the external IP addresses to be allowed to access 
the  modem router’s  remote management.
For enhanced security, restrict access to as few external IP addresses as practical.
Select one of the following:
• T
o allow access from a single IP address on the Internet, select the Only This 
Computer  radio button. Enter the IP address that will be allowed access. 
• T
o allow access from a range of IP addresses on the Internet, select the \
IP Address 
Range radio button. Enter a beginning and ending IP address. 
• T
o allow access from any IP address on the Internet, select the Everyone  radio 
button. 
7.  Specify the port number for accessing the web management interface.
Normal web browser access uses the standard HTTP service port 80. For gr\
eater 
security
 , enter a custom port number for the remote web management interface. Ch\
oose 
a number from 1024 to 65535, but do not use the number of any common ser\
vice port. 
The default is 8080, which is a common alternate for HTTP.
8.  Click the  Apply button. 
						

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82 N600 WiFi Cable Modem Router Model C3700 
Your changes take effect.
To use remote access:
1. Launch a web browser on a computer that is not on your home network.
2. Type your modem router’s WAN IP address into your browser’s address or location field 
followed by a colon (:) and the custom port number. 
For example, if your external address is 134.177.0.123 and you use port number 8080, 
enter http://134.177.0.123:8080 in your browser. 
						

							83
8
8.   Specify Internet Port Settings
You can use port forwarding and port triggering to set up rules for Internet traffic. You need 
networking knowledge to set up these features.
This chapter includes the following sections:
•Set Up Port Forwarding to a Local Server 
•Set Up Port Triggering  
						

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N600 WiFi Cable Modem Router Model C3700 
Set Up Port Forwarding to a Local Server
If you have a server in your home network, you can allow certain types o\
f incoming traffic to 
reach the server. For example, you might want to make a local web server, FTP server, or 
game server visible and available to the Internet.
The modem router can forward incoming traffic with specific protocols to computers on your  local network. 
 You can specify the servers for applications and you can also specify a d\
efault 
DMZ server to which the modem router forwards all other incoming protoco\
ls.
To forward specific incoming protocols:
1.  Decide which type of service, application, or game you want to provide.
2.  Find the local IP address of the computer on your network that will prov\
ide the service.
The server computer must always have the same IP address. To specify this setting, use  the reserved IP address feature. See Reserve LAN IP Addresses on page  51.
3.  Launch a web browser from a computer or wireless device that is connecte\
d to the network.
4.  T
ype  http://routerlogin.net  or http://192.168.0.1.
A login screen displays.
5.  Enter the  modem router  user name and password.
The user name is  admin. 
 The default password is password . The user name and 
password are case-sensitive.
The BASIC Home screen displays.
6.  Select  ADV
 ANCED > Advanced Setup > Port Forwarding/Port Triggering.
7. Leave the  Port Forwarding radio button selected as the service type.
8.  In the Service Name list, select the service name. 
						

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 N600 WiFi Cable Modem Router Model C3700
If the service that you want to add is not in the list, create a custom \
service. See 
Add a 
Custom Port Forwarding Service on page  85.
9.  In the Server IP 
 Address field, enter the IP address of the computer that will provide the 
service. 
10.  Click the  Add button.
The service displays in the list.
Add a Custom Port Forwarding Service
To add a custom service:
1.  Find out which port number or range of numbers the application uses.
You can usually find this information by contacting the publisher of the \
application or user  groups or news groups.
2.  Launch a web browser from a computer or wireless device that is connecte\
d to the network.
3.  T
ype  http://routerlogin.net  or http://192.168.0.1.
A login screen displays.
4.  Enter the modem router  user name and password.
The user name is  admin. 
 The default password is password. The user name and 
password are case-sensitive.
The BASIC Home screen displays.
5.  Select  ADV
 ANCED > Advanced Setup > Port Forwarding/Port Triggering.
6.  Leave the  Port Forwarding  radio button selected as the service type.
7.  Click the  Add Custom Service button.
8. In the Service Name field, enter a descriptive name. 
9.  In the Service T
 ype field, select the protocol. If you are unsure, select  TCP/UDP.
10.  In the External Starting Port field, enter the beginning port number
 . 
If the application uses a single port, enter the same port number in the\
  Ending Port field. 
						

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86 N600 WiFi Cable Modem Router Model C3700 
If the application uses a range of ports, enter the ending port number of the range in the 
External Ending Port field.
11. Type the port numbers in the Internal Starting Port and Internal Ending Port fields.
12. Type the IP address in the Internal IP address field or select the radio button for an 
attached device listed in the table.
13. Click the Apply button. 
The service is now in the list on the Port Forwarding/Port Triggering screen.
Edit a Port Forwarding Service
To edit a port forwarding entry:
1. Launch a web browser from a computer or wireless device that is connected to the 
network.
2. Type http://routerlogin.net or http://192.168.0.1.
A login screen displays.
3. Enter the modem router user name and password.
The user name is admin. The default password is password. The user name and 
password are case-sensitive.
The BASIC Home screen displays.
4. Select ADVANCED > Advanced Setup > Port Forwarding/Port Triggering.
5. Leave the Port Forwarding radio button selected as the service type.
6. In the table, select the radio button next to the service name.
7. Click the Edit Service button.
The Ports - Custom Services screen displays.
8. Specify changes to any of the following settings:
•Service Name. Type the service name.
•Service Type. If you are unsure, select TCP/UDP.
•External Starting Port. If the application uses a single port, enter the same port 
number in the External Ending Port field. If the application uses a range of ports, 
enter the ending port number of the range in the External Ending Port field.
•Internal Starting Port. By default, this is the same as the Internal Ending Port value. 
•Internal IP address. Type the IP address in the Internal IP address field, or select the 
radio button for an attached device listed in the table.
9. Click the Apply button.
Your changes are saved. 
						

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87  N600 WiFi Cable Modem Router Model C3700
Delete a Port Forwarding Entry
To delete a port forwarding entry:
1. Launch a web browser from a computer or wireless device that is connected to the 
network.
2. Type http://routerlogin.net or http://192.168.0.1.
A login screen displays.
3. Enter the modem router user name and password.
The user name is admin. The default password is password. The user name and 
password are case-sensitive.
The BASIC Home screen displays.
4. Select ADVANCED > Advanced Setup > Port Forwarding/Port Triggering.
5. Select the Port Forwarding radio button as the service type
6. In the table, select the radio button next to the service name.
7. Click the Delete Service button.
Application Example: Make a Local Web Server Public
If you host a web server on your local network, you can use port forwarding 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 address of 
192.168.0.33. 
2. In the Port Forwarding/Port Triggering screen, configure the modem router to forward the 
HTTP service to the local address of your web server at 192.168.0.33. 
HTTP (port 80) is the standard protocol for web servers.
3. (Optional) Register a host name with a Dynamic DNS service, and specify that name in the 
Dynamic DNS screen of the modem router. For more information, see 
Dynamic DNS on 
page 62.
Dynamic DNS makes it much easier to access a server from the Internet because you 
can type the name in the Internet browser. Otherwise, you must know the IP address that 
the ISP assigned, which typically changes. 
						

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88 N600 WiFi Cable Modem Router Model C3700 
How the Modem Router Implements the Port Forwarding Rule
The following sequence shows the effects of a port forwarding rule:
1. When you type 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. Your 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 192.168.0.123 
and sends the message to that computer.
4. Your web server at IP address 192.168.0.123 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 wireless device that sent the 
web page request. 
Set Up Port Triggering
Port triggering is a dynamic extension of port forwarding that is useful in these cases:
•An application uses port forwarding to more than one local computer (but not 
simultaneously).
•An application opens 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.
Note:If you use applications such as multiplayer gaming, peer-to-peer 
connections, real-time communications such as instant messaging, or 
remote assistance (a feature in Windows XP), enable Universal Plug 
and Play (UPnP). See 
Improve Network Connections with Universal 
Plug and Play on page 63. 
						

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 N600 WiFi Cable Modem Router Model C3700
Add a Port Triggering Service
To add a port triggering service:
1. 
Launch a web browser from a computer or wireless device that is connecte\
d to the 
network.
2.  T
ype  http://routerlogin.net  or http://192.168.0.1.
A login screen displays.
3.  Enter the modem router  user name and password.
The user name is  admin. 
 The default password is password. The user name and 
password are case-sensitive.
The BASIC Home screen displays.
4.  Select  ADV
 ANCED > Advanced Setup > Port Forwarding/Port Triggering. 
5.  Select the Port T
 riggering radio button.
6. Click the  Add Service button.
7. In the Service Name field, type a descriptive service name.  
						

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90 N600 WiFi Cable Modem Router Model C3700 
8. In the Service User list, select Any, or select Single address and enter the IP address of 
one computer:
•Any (the default) allows any computer on the Internet to use this service. 
•Single address restricts the service to a particular computer. 
9. Select the service type, either TCP or UDP or TCP/UDP (both). 
If you are not sure, select TCP/UDP.
10. In the Triggering Port field, enter the number of the outbound traffic port that will open the 
inbound ports. 
11. Enter the inbound connection port information in the Connection Type, Starting Port, and 
Ending Port fields.
12. Click the Apply button.
The service is now in the Portmap table. You must enable port triggering before the 
modem router uses port triggering for the service that you added. For information about 
port triggering, see 
Specify When to Use Port Triggering on page 90.
Specify When to Use Port Triggering
To specify when to use port triggering: 
1. Launch a web browser from a computer or wireless device that is connected to the 
network.
2. Type http://routerlogin.net or http://192.168.0.1.
A login screen displays.
3. Enter the modem router user name and password.
The user name is admin. The default password is password. The user name and 
password are case-sensitive.
The BASIC Home screen displays.
4. Select ADVANCED > Advanced Setup > Port Forwarding/Port Triggering.