PRIVATE IP ADDRESSES IS FOR PRIVATE LOCAL AREA NETWORKS, NOT FOR INTERNET
Most private networks do not require the allocation of globally routable, public IP addresses for every computer in the organization.
In particular, computers which are not public servers do not need to be addressable from the public Internet.
Organizations typically use IP addresses from the private address space for machines on the internal network.
There are currently three blocks of private address space reserved by Internet Assigned Numbers Authority (IANA):
10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.
These are defined in RFC1918 (https://tools.ietf.org/html/rfc1918). These addresses are not intended to be routed on the Internet, and are typically unique only within an organization or group of organizations which choose to follow the same numbering scheme.
The IP address is a “unique” sequence of numbers that identifies the DVR or other network device on a network and places it into an IP class.
This is comprised of a sequence of 4 batches (Octets) of 3 digit numbers which are then each separated by a full stop. e.g. 192.168.0.10, you can think of it as the PC equivalent of a postcode.
The Subnet Mask is a sequence of numbers that masks over a section of the devices IP address where this section is the same for each device connected to the network.
Where a “0” is present is where the digits in the IP addresses are unique so as to identify the different services.
Where 255’s are present is where the digits in the IP address are masked over and are unimportant.
For example
Computer IP Address
192.168.0.100
Subnet Mask
255.255.255.0
Gateway
192.168.0.1
DVR IP Address
192.168.0.200
Subnet Mask
255.255.255.0
Gateway
192.168.0.1
The Gateway is used when a device such as a DVR or computer is connected to the internet.
The Gateway address matches that of the INTERNAL address of the router that the device is connected to.
You can easily retrieve the routers internal address by using the “ipconfig” command detailed under IP Commands.
In the above example it is based on the router’s internal address being 192.168.0.1.