RP614v4 Cable/DSL Router Reference Manual

Advanced Configuration of the Router

4-5

v3.0, 2006-03

1.

From the Service & Game box, select the service or game that you will host on your network.

If the service does not appear in the list, refer to the following section, “

Adding a Custom

Service

”.

2.

Enter the IP address of the local server in the corresponding Server IP Address box.

3.

Click the

Add

button.

Adding a Custom Service

To define a service, game or application that does not appear in the Services & Games list, you

must determine what port numbers are used by the service. For this information, you may need to

contact the manufacturer of the program that you wish to use. When you have the port number

information, follow these steps:

1.

If port forwarding services are already configured, make a note of the Start Port and the End

Port used by each service.

2.

Click the

Add Custom Service

button.

Figure 4-4

3.

In the Service Name box, type a name.

4.

Enter an unused port number Starting Port box.

RP614v4 Cable/DSL Router Reference Manual

4-6

Advanced Configuration of the Router

v3.0, 2006-03

5.

To forward only one port, enter it again in the Ending Port box. To specify a range of ports,

enter the last port to be forwarded in the Ending Port box, making sure that the range of ports

being forwarded does not overlap with any currently configured services.

6.

Enter the IP address of the local server in the corresponding Server IP Address box.

7.

Click

Apply

at the bottom of the menu.

Editing or Deleting a Port Forwarding Entry

To edit or delete a Port Forwarding entry, follow these steps.

1.

In the table, select the button next to the service name.

2.

Click Edit or Delete.

Local Web and FTP Server Example

If a local computer with a private IP address of 192.168.1.33 acts as a Web and FTP server,

configure the Ports menu to forward HTTP (port 80) and FTP (ports 20 and 21) to local address

192.168.1.33.

To access this server from the Internet, the remote user must know the IP address that has been

assigned by your ISP. If this address is 172.16.1.23, for example, an Internet user can access your

Web server by directing the browser to http://172.16.1.23. The assigned IP address can be found in

the Router Status Menu, where it is shown as the WAN IP Address.

Some considerations for this application are:

•

If your account’s IP address is assigned dynamically by your ISP, the IP address may change

periodically as the DHCP lease expires.

•

If the IP address of the local computer is assigned by DHCP, it may change when the computer

is rebooted. To avoid this, you can manually configure the computer to use a fixed address.

•

Local computers must access the local server using the computers’ local LAN address

(192.168.1.33 in this example). Attempts by local computers to access the server using the

external IP address (172.16.1.23 in this example) will fail.

Multiple Computers for Internet Game Example

To set up an additional computer to play an Internet game:

1.

Select the game again from the Services/Games list.

RP614v4 Cable/DSL Router Reference Manual

Advanced Configuration of the Router

4-7

v3.0, 2006-03

2.

Change the beginning port number in the Start Port box.

For these games, use the supplied number in the default listing and add +1 for each additional

computer. For example, if you've already configured one computer to play Hexen II (using

port 26900), the second computer's port number would be 26901, and the third computer

would be 26902.

3.

Type the same port number in the End Port box that you typed in the Start Port box.

4.

Type the IP address of the additional computer in the Server IP Address box.

5.

Click Apply.

Some online games and videoconferencing applications are incompatible with NAT. The RP614v4

router is programmed to recognize some of these applications and to work properly with them, but

there are other applications that may not function well. In some cases, one local computer can run

the application properly if that computer’s IP address is entered as the default in the Ports Menu. If

one local computer acts as a game or videoconferencing host, enter its IP address as the default.

Configuring the WAN Setup Options

The WAN Setup options let you configure a DMZ server, change the MTU size and enable the

router to respond to a Ping on the WAN port. These options are discussed below.

Setting Up a Default DMZ Server

The default DMZ server feature is helpful when using some online games and videoconferencing

applications that are incompatible with NAT. The router is programmed to recognize some of these

applications and to work properly with them, but there are other applications that may not function

well. In some cases, one local computer can run the application properly if that computer’s IP

address is entered as the default DMZ server.

Incoming traffic from the Internet is normally discarded by the router unless the traffic is a

response to one of your local computers or a service that you have configured in the Ports menu.

Instead of discarding traffic for services you have not defined, you can have it forwarded to one

computer on your network. This computer is called the Default DMZ Server.

RP614v4 Cable/DSL Router Reference Manual

4-8

Advanced Configuration of the Router

v3.0, 2006-03

If you are willing to risk open access, the WAN Setup menu shown below lets you configure a

Default DMZ Server.

Figure 4-5

To assign a computer or server to be a Default DMZ server, follow these steps:

1.

Click the WAN Setup link on the Advanced section of the main menu.

2.

Check the Default DMZ Server box and type the IP address for that server. To remove the

default DMZ server, uncheck the Default DMZ Server box.

3.

Click

Apply

.

Disabling the SPI Firewall

The SPI (Stateful Packet Inpection) Firewall protects your LAN against Denial of Service

attacks. This should only be disabled in special circumstances.

Responding to Ping on the Internet WAN Port

If you want the router to respond to a 'ping' from the Internet, click the ‘Respond to Ping on

Internet WAN Port’ check box. This should only be used as a diagnostic tool, since it allows your

router to be discovered. Do not check this box unless you have a specific reason to do so.

RP614v4 Cable/DSL Router Reference Manual

Advanced Configuration of the Router

4-9

v3.0, 2006-03

Setting the MTU Size

The default MTU size is usually fine. The normal MTU (Maximum Transmit Unit) value for most

Ethernet networks is 1500 Bytes. For some ISPs, particularly some using PPPoE, you may need to

reduce the MTU to 1492. This should not be done unless you are sure it is necessary by your ISP.

Any packets sent through the router that are larger than the configured MTU size will be

repackaged into smaller packets to meet the MTU requirement. To change the MTU size:

1.

Under MTU Size, enter a new size between 64 and 1500.

2.

Click

Apply

to save the new configuration.

Using the LAN IP Setup Options

The second feature category under the Advanced heading is LAN IP Setup. This menu allows

configuration of LAN IP services such as DHCP and RIP. From the Main Menu of the browser

interface, under Advanced, click on LAN IP Setup to view the LAN IP Setup menu, shown below.

Figure 4-6