Draytek 2130 - Manual (Page 120)

Vigor2130 Series User’s Guide 112
Enable Click this radio button to invoke this function. However, IP/MAC
which is not listed in IP Bind List also can connect to Internet.
Disable Click this radio button to disable this function. All the settings on
this page will be invalid.
Strict Bind Click this radio button to block the connection of the IP/MAC
which is not listed in IP Bind List.
ARP Table This table is the LAN ARP table of this router. The information for
IP and MAC will be displayed in this field. Each pair of IP and
MAC address listed in ARP table can be selected and added to IP
Bind List by clicking Add below
.
Add and Edit IP Address – Type the IP address that will be used for the
specified MAC address.
Mac Address – Type the MAC address that is used to bind with
the assigned IP address.
Refresh It is used to refresh the ARP table. When there is one new PC
added to the LAN, you can click this link to obtain the newly ARP
table information.
IP Bind List It displays a list for the IP bind to MAC information.
Add It allows you to add the one you choose from the ARP table or the
IP/MAC address typed in Add and Edit to the table of IP Bind
List.
Edit It allows you to edit and modify the selected IP address and MAC
address that you create before.
Remove You can remove any item listed in IP Bind List. Simply click and
select the one, and click Remove. The selected item will be
removed from the IP Bind List.
Note: Before you select Strict Bind, you have to bind one set of IP/MAC address for one
PC. If not, no one of the PCs can access into Internet. And the web configurator of the router
might not be accessed.
4 4 . . 3 3 N N A A T T
Usually, the router serves as an NAT (Network Address Translation) router. NAT is a
mechanism that one or more private IP addresses can be mapped into a single public one.
Public IP address is usually assigned by your ISP, for which you may get charged. Private IP
addresses are recognized only among internal hosts.
When the outgoing packets destined to some public server on the Internet reach the NAT
router, the router will change its source address into the public IP address of the router, select
the available public port, and then forward it. At the same time, the router shall list an entry in
a table to memorize this address/port-mapping relationship. When the public server response,
the incoming traffic, of course, is destined to the router’s public IP address and the router will
do the inversion based on its table. Therefore, the internal host can communicate with external
host smoothly.
The benefit of the NAT includes:
z
Save cost on applying public IP address and apply efficient usage of IP address.
NAT allows the internal IP addresses of local hosts to be translated into one public IP
address, thus you can have only one IP address on behalf of the entire internal hosts.