Domain Controllers
DCs handle logins from your **Active Directory** (AD). They ensure only authorized users can login and access certain resources by checking credentials.
IP address formats
There are about 4.3 billion IPv4 addresses possible in the world right now. In a ip address 192.168.1.204 with a subnet mask of 255.255.255.0 the first three octects represent the network portion while the last is the host portion. 256 addresses are available but in reality 2 are resereved by default for the Network address and the Broadcast address. Making 253 usable.
| Class A | Class B | Class C | Class D | Class E |
|---|---|---|---|---|
| 1.0.0.0 – 126.255.255.255 | 128.0.0.0 – 191.255.0.0 | 192.0.0.0 – 223.255.255.0 | 224.0.0.0 – 239.255.255.255 | 240.0.0.0 – 255.255.255.255 |
| Class A | Class B | Class C | Class D | Class E |
|---|---|---|---|---|
| 255.0.0.0 | 255.255.0.0 | 255.255.255.0 | Multicast | Experimental |
RFCI1918
RFCI19 was created when the scare of running out of IP addresses came apon us, thus Private IP addresses were born. The private addresses are something eveyone has and uses some might even be the same, but they remain private in your own network. Whenever someone wants to talk outside the network, lets say browse the internet, our private then turns to public using NAT (Network Address Translation). Every device in your network?home will talk to the internet with the same public IP given out by NAT!
