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6.6 Router & Port Forwarding
A majority of networks will often consist of a single IP address which shares internet access
through a router. This IP address may be any external (public) static IP address or any
dynamic IP address issued by the Internet Service Provider.
The purpose of a router is to enable multiple personal computers and any other devices that
require internet connection to access the internet simultaneously. Most routers by default
enable (open) commonly used ports so that mainstream applications such as Hypertext
Transfer Protocol (HTTP, Port 80), File Transfer Protocol (FTP, Port 21), Telnet (Port 23) and
Post Office Protocol 3 (POP3, Port 110) are used.
To solve the firewall problem, and let a visitor into the network, the user instructs the router to
allow traffic to pass through on a given port. This is known as Port Forwarding, as the router
forwards (directs) all internet requests on a specific port to the local machine. With port
forwarding, external visitors are able to connect to the DVR while other internal devices
remain protected.
Here is the example of DVR connection.
Network Router DVR IP Setting
PC Connect position PC Connect position CF
LAN WAN
A B C B C
Static IP
use
STATIC
DHCP Check the DVR IP of info
and set into Router.
x
STATIC
DHCP N/A [Need Local DHCP
Server]
DHCP
use
STATIC
DHCP Check the DVR IP of info
and set into Router
x
STATIC N/A
DHCP PPPOE is not supported