1. Home
    2. /
  2. Manuals
    3. /
  3. Telewell
    4. /
  4. TW-EA510v4
    5. /
  5. 18
Page 86 / 110 Scroll up to view Page 81 - 85
TW-EA510 version 4 ADSL2+, WLAN 802.11g, VPN, Firewall Router
Chapter 4: Configuration
85
Virtual Server (“Port Forwarding”)
In TCP/IP and UDP networks a port is a 16-bit number used to identify which application program
(usually a server) incoming connections should be delivered to. Some ports have numbers that are pre-
assigned to them by the IANA (the Internet Assigned Numbers Authority), and these are referred to as
“well-known ports”. Servers follow the well-known port assignments so clients can locate them.
If you wish to run a server on your network that can be accessed from the WAN (i.e. from other
machines on the Internet that are outside your local network), or any application that can accept
incoming connections (e.g. Peer-to-peer/P2P software such as instant messaging applications and P2P
file-sharing applications) and are using NAT (Network Address Translation), then you will usually need to
configure your router to forward these incoming connection attempts using specific ports to the PC on
your network running the application. You will also need to use port forwarding if you want to host an
online game server.
The reason for this is that when using NAT, your publicly accessible IP address will be used by and point
to your router, which then needs to deliver all traffic to the private IP addresses used by your PCs.
Please see the
WAN
configuration section of this manual for more information on NAT.
The device can be configured as a virtual server so that remote users accessing services such as Web
or FTP services via the public (WAN) IP address can be automatically redirected to local servers in the
LAN network. Depending on the requested service (TCP/UDP port number), the device redirects the
external service request to the appropriate server within the LAN network
Page 87 / 110
TW-EA510 version 4 ADSL2+, WLAN 802.11g, VPN, Firewall Router
Chapter 4: Configuration
86
Add Virtual Server
Because NAT can act as a “natural” Internet firewall, your router protects your network from being
accessed by outside users when using NAT, as all incoming connection attempts will point to your router
unless you specifically create Virtual Server entries to forward those ports to a PC on your network.
When your router needs to allow outside users to access internal servers, e.g. a web server, FTP server,
Email server or game server, the router can act as a “virtual server”. You can set up a local server with a
specific port number for the service to use, e.g. web/HTTP (port 80), FTP (port 21), Telnet (port 23),
SMTP (port 25), or POP3 (port 110), When an incoming access request to the router for a specified port
is received, it will be forwarded to the corresponding internal server.
Time Schedule:
A self-defined time period to enable your virtual server.
You may specify a time
schedule or Always on for the usage of this Virtual Server Entry.
For setup and detail, refer to
Time
Schedule
section
Application
: Users-define description to identify this entry or click
to select existing
predefined rules.
:
20 predefined rules are available.
Click the Radio button to select the rule; Application,
Protocol and External/Redirect Ports will be filled after the selection.
Protocol
: It is the supported protocol for the virtual server. In addition to specifying the port number to
be used, you will also need to specify the protocol used. The protocol used is determined by the
particular application. Most applications will use TCP or UDP.
External Port:
The Port number on the Remote/WAN side used when accessing the virtual server.
Redirect Port:
The Port number used by the Local server in the LAN network.
Page 88 / 110
TW-EA510 version 4 ADSL2+, WLAN 802.11g, VPN, Firewall Router
Chapter 4: Configuration
87
Internal IP Address:
The private IP in the LAN network, which will be providing the virtual server
application.
List all existing PCs connecting to the network. You may assign a PC with
IP address and MAC from this list.
Example:
If you like to remote accessing your Router through the Web/HTTP at all time, you would need to enable
port number 80 (Web/HTTP) and map to Router’s IP Address.
Then all incoming HTTP requests from
you (Remote side) will be forwarded to the Router with IP address of 192.168.0.254.
Since port number
80 has already been predefined, next to the
Application
click
Helper.
A list of predefined rules window
will pop and select
HTTP_Sever
.
Application:
HTTP_Sever
Time Schedule:
Always On
Protocol:
tcp
External Port:
80-80
Redirect Port:
80-80
IP Address:
192.168.0.254
Edit:
Click it to edit this virtual server application.
Delete:
Click it to delete this virtual server application.
If you have disabled the NAT option in the WAN-ISP section, the Virtual Server function
will hence be invalid.
If the DHCP server option is enabled, you have to be very careful in assigning the IP
addresses of the virtual servers in order to avoid conflicts. The easiest way of configuring
Virtual Servers is to manually assign static IP address to each virtual server PC, with an
address that does not fall into the range of IP addresses that are to be issued by the DHCP
server. You can configure the virtual server IP address manually, but it must still be in the
same subnet as the router.
Attention
Using port forwarding does have security implications, as outside users will be able to
connect to PCs on your network. For this reason you are advised to use specific Virtual
Server entries just for the ports your application requires, instead of using DMZ. As
doing so will result in all connections from the WAN attempt to access to your public IP
of the DMZ PC specified.
Page 89 / 110
TW-EA510 version 4 ADSL2+, WLAN 802.11g, VPN, Firewall Router
Chapter 4: Configuration
88
Edit DMZ Host
The DMZ Host is a local computer exposed to the Internet. When setting a particular internal IP address
as the DMZ Host, all incoming packets will be checked by the Firewall and NAT algorithms then passed
to the DMZ host, when a packet received does not use a port number used by any other Virtual Server
entries.
Cautious:
This Local computer exposing to the Internet may face varies of security risks
.
±
Disabled:
As set in default setting, it disables the DMZ function.
±
Enabled:
It activates your DMZ function.
Internal IP Address:
Give a static IP address to the DMZ Host when
Enabled
radio button is checked.
Be aware that this IP will be exposed to the WAN/Internet.
Listed all existing PCs connecting to the network. You may assign a PC with IP address
and MAC from this list.
Select the
Apply
button to apply your changes.
Page 90 / 110
TW-EA510 version 4 ADSL2+, WLAN 802.11g, VPN, Firewall Router
Chapter 4: Configuration
89
Edit One-to-One NAT (Network Address Translation)
One-to-One NAT maps a specific private/local IP address to a global/public IP address.
If you have multiple public/WAN IP addresses from you ISP, you are eligible for One-to-One NAT to
utilize these IP addresses.
NAT Type:
Select desired NAT type. As set in default setting, it disables the One-to-One NAT function.
Global IP Address:
±
Subnet:
The subnet of the public/WAN IP address given by your ISP.
If your ISP has provided
this information, you may insert it here.
Otherwise, use IP Range method.
±
IP Range:
The IP address range of your public/WAN IP addresses. For example, IP:
192.168.0.1, end IP: 192.168.0.10
Select the
Apply
button to apply your changes.
Check
to create a new One-to-One NAT rule:

Rate

4 / 5 based on 1 vote.

Popular Telewell Models

Famous Router IPs
Famous Router Companies
Bookmark Our Site

Press Ctrl + D to add this site to your favorites!

Share
Top