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71

C

HAPTER

10

WAN

10.1

Overview

This chapter discusses the NBG6817’s

WAN

screens. Use these screens to configure your NBG6817

for Internet access.

A WAN (Wide Area Network) connection is an outside connection to another network or the

Internet. It connects your private networks such as a LAN (Local Area Network) and other

networks, so that a computer in one location can communicate with computers in other locations.

Figure 51

LAN and WAN

10.2

What You Can Do

•

Use the

Internet Connection

screen to enter your ISP information and set how the computer

acquires its IP, DNS and WAN MAC addresses (

Section 10.4 on page 74

).

•

Use the

NAT > General

screen to enable NAT, set a default server and change your NBG6817’s

port forwarding settings (

Section 10.5.1 on page 86

).

•

Use the

NAT > Port Trigger

screen to configure your NBG6817’s trigger port settings (

Section

10.5.2 on page 88

).

•

Use the

NAT > Passthrough

screen to configure your NBG6817’s ALGs and VPN pass-through

settings (

Section 10.5.3 on page 88

).

•

Use the

Dynamic

DNS

screen to change your NBG6817’s DDNS settings (

Section 10.6 on page

90

).

10.3

What You Need To Know

The information in this section can help you configure the screens for your WAN connection, as well

as enable/disable some advanced features of your NBG6817.

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10.3.1

Configuring Your Internet Connection

Encapsulation Method

Encapsulation is used to include data from an upper layer protocol into a lower layer protocol. To set

up a WAN connection to the Internet, you need to use the same encapsulation method used by your

ISP (Internet Service Provider). If your ISP offers a dial-up Internet connection using PPPoE (PPP

over Ethernet) or PPTP (Point-to-Point Tunneling Protocol), they should also provide a username

and password (and service name) for user authentication.

WAN IP Address

The WAN IP address is an IP address for the NBG6817, which makes it accessible from an outside

network. It is used by the NBG6817 to communicate with other devices in other networks. It can be

static (fixed) or dynamically assigned by the ISP each time the NBG6817 tries to access the

Internet.

If your ISP assigns you a static WAN IP address, they should also assign you the subnet mask and

DNS server IP address(es) (and a gateway IP address if you use the Ethernet or ENET ENCAP

encapsulation method).

DNS Server Address Assignment

Use Domain Name System (DNS) to map a domain name to its corresponding IP address and vice

versa, for instance, the IP address of www.zyxel.com is 204.217.0.2. The DNS server is extremely

important because without it, you must know the IP address of a computer before you can access

it.

The NBG6817 can get the DNS server addresses in the following ways.

1

The ISP tells you the DNS server addresses, usually in the form of an information sheet, when you

sign up. If your ISP gives you DNS server addresses, manually enter them in the DNS server fields.

2

If your ISP dynamically assigns the DNS server IP addresses (along with the NBG6817’s WAN IP

address), set the DNS server fields to get the DNS server address from the ISP.

WAN MAC Address

The MAC address screen allows users to configure the WAN port's MAC address by either using the

factory default or cloning the MAC address from a computer on your LAN. Choose

Factory Default

to select the factory assigned default MAC Address.

Otherwise,

click

Clone the computer's MAC address - IP Address

and enter the IP address of

the computer on the LAN whose MAC you are cloning. Once it is successfully configured, the

address will be copied to configuration file. It is recommended that you clone the MAC address prior

to hooking up the WAN Port.

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Multicast

Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender - 1 recipient)

or Broadcast (1 sender - everybody on the network). Multicast delivers IP packets to a group of

hosts on the network - not everybody and not just 1.

Figure 52

Multicast Example

In the multicast example above, systems A and D comprise one multicast group. In multicasting,

the server only needs to send one data stream and this is delivered to systems A and D.

IGMP (Internet Group Multicast Protocol) is a network-layer protocol used to establish membership

in a multicast group - it is not used to carry user data. The NBG6817 supports both IGMP version 1

(

IGMP-v1

) and IGMP version 2 (

IGMP-v2

).

At start up, the NBG6817 queries all directly connected networks to gather group membership.

After that, the NBG6817 periodically updates this information. IP multicasting can be enabled/

disabled on the NBG6817 WAN interface in the Web Configurator (

WAN

). Select

None

to disable IP

multicasting on these interfaces.

Auto-IP Change

When the NBG6817 gets a WAN IP address or a DNS server IP address which is in the same subnet

as the LAN IP address 192.168.1.1, Auto-IP-Change allows the NBG6817 to change its LAN IP

address to 10.0.0.1 automatically. If the NBG6817’s original LAN IP address is 10.0.0.1 and the

WAN IP address is in the same subnet, such as 10.0.0.3, the NBG6817 switches to use 192.168.1.1

as its LAN IP address.

Figure 53

Auto-IP-Change Example

192.168.1.1

192.168.1.23

10.0.0.1

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Auto-IP-Change only works under the following conditions:

•

The NBG6817 must be in

Router Mode

(see

Section 15.12 on page 158

for more information)

for Auto-IP-Change to become active.

•

The NBG6817 is set to receive a dynamic WAN IP address.

10.4

Internet Connection Screen

Use this screen to change your NBG6817’s Internet access settings. Click

Expert

Mode

>

WAN

>

Internet Connection

.

10.4.1

IPoE Encapsulation

This screen displays when you select

IPoE

encapsulation.

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Figure 54

Expert Mode > WAN > Internet Connection: IPoE Encapsulation (IPv4 Only)