Configuring Your Gateway

5. To change the settings for a customer-defined service, click the radio button to the left of

the service you want to change and click the

Edit

button. When the Customer Defined

Service menu appears, edit the settings as necessary (see Table 10) and click

Apply

.

Click

Apply

in the LAN Settings menu to save your settings.

6. To delete a customer-defined service, click the radio button to the left of the service you

want to delete and click the

Delete

button. No precautionary message appears before you

delete a customer-defined service, so be sure you no longer need the service before you

delete it. Click

Apply

in the LAN Settings menu to save your settings.

Figure 26. Customer Defined Service Menu

46

SMCD3GN Wireless Cable Modem Gateway User Manual

Configuring Your Gateway

Table 13. Customer Defined Service Page Options

Option

Description

Name

Name for identifying the custom service. The name is for reference purposes only.

Type

The type of protocol. Choices are TCP, UDP, and TCP/UDP. Default is TCP.

LAN Server IP

IP address of the LAN PC or server that is running the service.

Remote IPs

Forwards the service to any remote IP address, one remote IP address, or a range of remote IP

addresses.

Start IP

To specify:

•

A single remote IP address, enter the remote IP address.

•

A range of remote IP addresses, enter the starting IP address here and the ending IP address range in

the next field.

This field is unavailable if the Gateway is configured for any remote IP addresses.

End IP

Ending IP address in the remote IP address range. This field is unavailable if the Gateway is configured for

any remote IP addresses or a single remote IP address.

Public IP Ports

A single public IP port or a range of public IP ports on which the service is provided. If necessary, contact

the application vendor for this information.

Start Public Port

Starting number of the port on which the service is provided.

End Public Port

Ending number of the port on which the service is provided. This field is unavailable if the Gateway is

configured for a single public IP port.

Private Ports

Numbers of the ports whose traffic the Gateway forwards to the LAN. If there is a range of ports, enter the

starting private port here and check

Enable Port Range

. The Gateway automatically calculates the end

private port. The LAN PC server listens for traffic/data on this port (or these ports).

47

SMCD3GN Wireless Cable Modem Gateway User Manual

Configuring Your Gateway

Security Settings (Firewall) Menu

The Security Settings (Firewall) menu lets you enable or disable the Gateway’s firewall. In

addition, the submenus associated with this menu let you:

y

Configure access control settings

⎯

see page 49

y

Configure your Gateway for special applications

⎯

see page 49

y

Set up URL blocking

⎯

see page 52

y

Schedule routes

⎯

see page 54

y

Receive email or syslog alert notifications

⎯

see page 55

y

Configure a local client computer as a local DMZ for unrestricted two-way Internet

access

⎯

see page 58

Enabling or Disabling Firewall

The Security Settings (Firewall) menu provides an option for enabling or disabling the

Gateway’s firewall setting. To access the Security Settings (Firewall) menu, click

Firewall

in

the menu bar. Figure 27 shows an example of the menu.

By default, your Gateway’s firewall settings are enabled. To disable the firewall, uncheck

Enable Firewall Mode

.

Figure 27. Firewall Settings (Security) Menu

48

SMCD3GN Wireless Cable Modem Gateway User Manual

Configuring Your Gateway

Configuring Access Control

The Access Control menu lets you enable access control to block traffic at the Gateway's

LAN interfaces from accessing the Internet.

To access the Access Control menu, click

Firewall

in the menu bar and then click the

Access Control

submenu in the menu bar.

By default, your Gateway does not block attempts to access the LAN from the Internet. To

enable access control, check

Enable Access Control.

Figure 28. Access Control Menu

Configuring Special Applications

Using the Special Application menu, you can configure your Gateway to detect port triggers

for detect multiple-session applications and allow them to pass the firewall. For special

applications, besides the initial communication session, there are multiple related sessions

created during the protocol communications. Normally, a normal treats the triggered

sessions as independent sessions and blocks them. However, your Gateway can co-relate

the triggered sessions with the initial session and group them together in the NAT session

table. As a result, you need only specify which protocol type and port number you want to

track, as well as some other related parameters. In this way, the Gateway can pass the

special applications according to the supplied information.

49

SMCD3GN Wireless Cable Modem Gateway User Manual

Configuring Your Gateway

Assume, for example, that to use H.323 in a Net Meeting application, a local client starts a

session A to a remote host. The remote host uses session A to communicate with the local

host, but it also could initiate another session B back to the local host. Since there is only

session A recorded in the NAT session table when the local host starts the communication,

session B is treated as an illegal access from the outside and is blocked. Using the Special

Application menu, you can configure the Gateway to co-relate sessions A and B and

automatically open the port for the incoming session B.

The maximum allowed triggers is 50. To enable/disable the special application function,

users can check/uncheck the Enable Triggering checkbox and press the APPLY icon to

make it effective without reboot.

To display the Special Applications menu, click

Firewall

in the menu bar and then click the

Special Application

submenu. Figure 29 shows an example of the menu.

Figure 29. Special Applications Menu

To enable port triggering:

1. In the Special Application menu, check

Enable Triggering

and click the

Apply

button. The

Trigger Table becomes available.

2. Click the

Add

button below the table. The Trigger menu appears (see Figure 30).

50

SMCD3GN Wireless Cable Modem Gateway User Manual