Orite ic301, Руководство пользователя

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10-1. WAN IP Address
The WAN (Wide Area Network) IP address that your Internet Service Provider provides you so
that you can access the Internet is very different from the LAN or local IP address that your
PCs and cameras are using to connect to your local network. Your WAN or Internet IP
address is visible to the outside world (Internet) whereas your local addresses are not. To find
your home or business network from the Internet you must know your WAN IP address.
Your WAN IP address is stored by your gateway router, which uses it to connect to the Internet.
All the devices on your network connect to the Internet via your gateway router. You can find
your current WAN IP address by checking your router status page. There are also various
websites such as www.whatismyip.com which, will tell you the IP address that you are
currently using to access the Internet.
A word about terminology
The term gateway is used generically to define a device that connects a local network to the
Internet. A gateway may be a router, a PC running software which allows it to act as a
gateway such as a proxy server, or some other device. Most home networks use a NAT
(Network Address Translation) router as a gateway. The term gateway router refers to such a
device.
Static versus Dynamic IP address
The IP address (or addresses) your ISP has (have) provided you will either be static, which
means it never changes, or dynamic, meaning it can change periodically. Dynamic addresses
present an additional challenge when trying to locate your network from the Internet since
your address may have changed since the last time you checked it. How often your dynamic
address changes varies from one service provider to another. Also, any time you reboot your
cable or DSL modem, you are likely to get a new address when reconnecting. The solution to
the ever-changing IP address is known as DDNS or dynamic domain name service. A DDNS
will allow you to find your network by a domain name, such as mynetcam.no-ip.com, rather
than needing to know the IP address.
10-2. Network Address Translation (NAT)
Most home routers and business firewalls today perform something called NAT or Network
Address Translation. NAT translates your external or WAN IP address into an internal address
inside your gateway router. What this means is, you can think of your router as being divided
into two halves, the LAN side (inside) and the WAN side (outside or Internet side). When a
connection request arrives at your router from the Internet, it will not get any farther than the
WAN side unless you have specifically instructed your router to pass this type of request to a
specific device on your LAN. This process is know as port forwarding or port redirecting.