NETCOMM GATEWAY™ SERIES –

NB304N – ADSL2+ Wireless N300 Modem Router

26

NetComm NB304N – ADSL2+ Wireless N300 Modem

YML304X

www.netcomm.com.au

NAT

NAT stands for Network Address Translation, a process which converts private IP addresses of a computer on the internal private

network to one or more public IP addresses for the Internet. NAT changes the packet headers to the new address and keeps track

of each session; when packets come back from the Internet, it performs the reverse conversion to the IP address of the client

machine.

Virtual Servers

Virtual Server allows you to direct incoming traffic from the Internet to a specific computer in your local network. A maximum 32

entries can be configured.

Click Add to create a Virtual Server.

As an example, to setup a web server on a computer using 192.168.1.88 as its IP Address, select HTTP as Service and enter

192.168.1.88 as the Server IP Address. Otherwise if the service you want to setup is not available from the Select a Service drop-

down list, you can define your own Virtual Server.

1.

Enter the IP Address to forward the incoming connections to.

2.

Enter the External Port range for the incoming connections

3.

Select the appropriate protocol

4.

Enter the Internal Port Range

Click Save/Apply to save the new Virtual Server configuration settings.

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NetComm NB304N – ADSL2+ Wireless N300 Modem

YML304X

Port Triggering

Some applications require that the specific ports in the router’s firewall be opened for access by the remote parties. For instance, an

application uses port 25 for requests and port 113 for replies. If a computer on the LAN connects to port 25 on a remote server

hosting this application, using Port Triggering on the router, incoming connections to port 113 (from the remote server) could be

redirected to the PC which initiated the request. A maximum of 32 entries can be configured.

Click Add to setup Port Triggering.

1.

Enter the External Port range for the incoming connections

2.

Select the appropriate protocol

3.

Enter the Internal Port Range

Click Save/Apply to save the new Port Trigger configuration settings.

DMZ Host

If a computer is assigned as a DMZ Host, it will receive all the data from the Internet that does not belong to the list of applications

configured as a Virtual Server. Enter the LAN IP address of the PC you wish to set as DMZ Host in the DMZ Host IP Address. If you

need to disable the DMZ Host, just clear the DMZ Host IP Address field, and then click Save/Apply.

Please note: The DMZ exposes your computer to the Internet. Ensure appropriate steps are taken to protect it.

NETCOMM GATEWAY™ SERIES –

NB304N – ADSL2+ Wireless N300 Modem Router

28

NetComm NB304N – ADSL2+ Wireless N300 Modem

YML304X

www.netcomm.com.au

ALG

An Application Layer Gateway (ALG) allows two or more simultaneous NAT connections to be made by clients through this router.

Select the specific ALG NAT functions to enable and click Save/Apply.

Multi NAT

Multi NAT enables the NB304N to support a number of different NAT types such as:



One to One



One to Many



Many to One



Many to Many

1.

Select the type of NAT to use from the Rule Type dropdown menu.

2.

Select the interface to apply the NAT rule to

3.

Enter the appropriate Internal Address Start and Internal Address End

4.

Enter the appropriate External Address Start and External Address End

5.

Click Save/Apply to save the new Multi NAT configuration settings.

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29

NetComm NB304N – ADSL2+ Wireless N300 Modem

YML304X

Security

IP Filtering

The router supports IP Filtering which allows you to easily set up rules to control incoming and outgoing Internet traffic. The router

provides two types of IP filtering: Outgoing IP Filtering and Incoming IP Filtering.

Outgoing IP Filtering

By default, the router allows all outgoing Internet traffic from the LAN but by setting up Outgoing IP Filtering rules, you can block

some users and/or applications from accessing the Internet.

To delete the rule, click Remove checkbox next to the selected rule and click Remove.

To create a new outgoing IP filter, click Add. The Add IP Filter-Outgoing page will be displayed.

Enter the following parameters:

PARAMETER

DEFINITION

Filter Name

Enter a name to identify the filtering rule

IP Version

Select the IP version to apply the filter to.

Protocol

Select the protocol type to block

Source IP Address/Subnet Mask

Enter the IP Address of the PC on the LAN to block

Source Port

Enter the port number used by the application to block

Destination IP Address/Subnet Mask

Enter the IP Address of the Remote Server to which connections should be blocked

Destination Port

Enter the destination port number used by the application to block

Click Save/Apply to take effect the settings. The new rule will then be displayed in the Outgoing IP Filtering table list.

NETCOMM GATEWAY™ SERIES –

NB304N – ADSL2+ Wireless N300 Modem Router

30

NetComm NB304N – ADSL2+ Wireless N300 Modem

YML304X

www.netcomm.com.au

Incoming IP Filtering

By default, when NAT is enabled, all incoming IP traffic from WAN is blocked except for responses to requests from the LAN.

However, some incoming traffic from the Internet can be accepted by setting up Incoming IP Filtering rules.

To delete the rule, click Remove checkbox next to the selected rule and click Remove.

To create a new incoming IP filter, click Add. The Add IP Filter-Incoming page will be displayed.

Enter the following parameters:

PARAMETER

DEFINITION

Filter Name

Enter a name to identify the filtering rule

IP Version

Select the IP version to apply the filter to

Protocol

Select the protocol type to allow

Source IP Address/Subnet Mask

Enter the IP Address of the Remote Server from which to allow connections

Source Port

Enter the port number used by the application to allow

Destination IP Address/Subnet Mask

Enter the IP Address of the PC on the LAN to which connections should be allowed

Destination Port

Enter the destination port number used by the application to allow

WAN Interface

Select the WAN Interface to apply the filter to

Click Save/Apply to take effect the settings. The new rule will then be displayed in the Incoming IP Filtering table list.

MAC Filtering

The NB304N offers the ability to utilise MAC Address filtering on ATM PVCs. You can elect to block or allow connections based on

MAC Address criteria. The default policy is to allow connections which match the criteria. Click Add to enter a new MAC Address

filter.

1.

Enter the Protocol type to apply the filter to

2.

Enter the Source and Destination MAC Address

3.

Enter the direction of the traffic to filter

4.

Select the WAN interface to apply to the filter to.

Click Apply/Save to save the new MAC filtering configuration.