26

Host & Group

List

This table shows the current bindings.

5.2

Routing

This section is only relevant if your LAN has other Routers or Gateways.

y

If you don't have other Routers or Gateways on your LAN, you can ignore the

Static

Routing

page completely.

y

If your LAN has other Gateways and Routers, you must configure the Static Routing

screen as described below. You also need to configure the other Routers.

Figure: Routing

Note:

If there is an entries in the Routing table with an Index of zero (0), these are System entries.

You cannot modify or delete these entries.

Settings – Routing

Dynamic

Routing

•

RIP v2

– RIP is a dynamic routing protocol which is used to

direct traffic over the network. Disable it if you don't need to

use it.

•

LAN and WAN1

– If enabled, any WAN or LAN can execute

RIP function.

Static Routing

If there is more than one router on a network, this Routing table

must be configured because the router needs to know what packet

goes to which router. A routing table entry is required for each LAN

segment on the network

•

Network Address

– The address of the destination network

27

segment.

•

Netmask

–The subnet mask used to select the bits from an IP

Address that corresponds to the subnet.

•

Gateway

–The router that the packets destined for the subnet

with

Network Address

will be forwarded to.

•

Interface

– The device's port that the packets destined for the

subnet with Network Address will be passed through.

•

Metric

– The number of routers that must be traversed to

reach the destination network segment

Routing List

List of static route that you configured previously.

Configuring Other Routers on your LAN

All traffic for devices not on the local LAN must be forwarded to the Router, so that they

can be forwarded to the Internet. This is done by configuring other Routers to use the

Router as the Default Route or Default Gateway, as illustrated by the example below.

Static Routing – Example

Router B

(192.168.2.90)

(192.168.3.70)

Router A

Segment 0

Segment 2

Segment 1

(192.168.1.xx)

(192.168.2.xx)

(192.168.1.100)

(192.168.1.1)

(192.168.3.xx)

(192.168.2.80)

Figure: Routing Example

y

For the Router Gateway's Routing Table

For the LAN shown above, with 2 routers and 3 LAN segments, the Router requires 2

entries as follows.

Entry 1 (Segment 1)

Destination IP Address

192.168.2.0

Network Mask

255.255.255.0

Gateway IP Address

192.168.1.100

Interface

LAN

Metric

2

Entry 2 (Segment 2)

Destination IP Address

192.168.3.0

28

Network Mask

255.255.255.0

(Standard Class C)

Gateway IP Address

192.168.1.100

Interface

LAN

Metric

3

y

For Router A's Default Route

Destination IP Address

0.0.0.0

Network Mask

0.0.0.0

Gateway IP Address

192.168.1.1

Metric

2

y

For Router B's Default Route

Destination IP Address

0.0.0.0

Network Mask

0.0.0.0

Gateway IP Address

192.168.2.80

Interface

LAN

Metric

3

5.3

Virtual Servers

This feature allows you to make Servers on your LAN accessible to Internet users.

Normally, Internet users would not be able to access a server on your LAN because:

y

Your Server's IP address is only valid on your LAN, not on the Internet.

y

Attempts to connect to devices on your LAN are blocked by the firewall in the Router.

The "Virtual Server" feature solves these problems and allows Internet users to connect to

your servers, as illustrated below.

Figure: Virtual Servers

29

Note that, in this illustration, both Internet users are connecting to the same IP Address,

but using different protocols.

Connecting to the Virtual Servers

Once configured, anyone on the Internet can connect to your Virtual Servers. They must

use the Router's Internet IP Address (the IP Address allocated by your ISP).

e.g.:

http://205.20.45.34

ftp://205.20.45.34

•

To Internet users, all virtual Servers on your LAN have the same IP Address. This IP

Address is allocated by your ISP.

•

This address should be static, rather than dynamic, to make it easier for Internet users

to connect to your Servers. However, you can use the

Dynamic DNS

feature (explained

later in this chapter) to allow users to connect to your Virtual Servers using a URL,

instead of an IP Address.

e.g.

HTTP://my_domain_name.dyndns.org

FTP://my_domain_name.dyndns.org

Figure: Virtual Server

Settings – Virtual Server

30

Virtual Server

Configuration

•

Enable

– To activate or deactivate the current entry.

•

Server Name

– A unique name for identifying the virtual

server.

•

Protocol

– Select the protocol (either TCP or UDP) used

by the server software.

•

IP Address

–

LAN:

Enter the IP address of the server on

the device's LAN side. The hosts used as Virtual Servers

need static IP addresses or reserved IP addresses.

WAN:

The WAN port that the virtual server is bound on.

•

Port Range

–

LAN:

The range of port numbers used by

the server. If only one port number is used, fill the same

number in both starting and ending fields.

WAN:

The

range of port numbers for users in public to access the

virtual server. If only one port number is used, fill the same

number in both starting and ending fields.

•

Allowed Remote IP

– The range of IP addresses that are

allowed to access the virtual server.

Virtual Server List

The Virtual Server List shows details of all Virtual Servers which

have been defined.

5.4

Special Applications

If you use Internet applications which have non-standard connections or port numbers, you

may find that they do not function correctly because they are blocked by the firewall in the

Router. In this case, you can define the application as a "Special Application" in order to

make it work.

Note that the terms "Incoming" and "Outgoing" on this screen refer to traffic from the client

(PC) viewpoint

Figure: Special Applications