L
legacy-fate
Guest
IP address structure:
---.---.---.---
^ ^
| |
network | host
Every " --- " = 8 bits.
The first bits ===> network address
The last bits ===> host address.
with 8 bits you can present from 0-255 . (binary=(2 to the power of 8)-1)
Example:
11000010.01011010.00011111.01001010 (binary)
194.90.31.74 (decimal)
IP address CLASSES :
We can classify IP addreses to 5 groups. You can distinguish them by comparing the "High Order" bits (the first four bits on the
left of the address):
type | model | target | MSB |addr.range |bit number| max.stations|
| | groups | | |net./hosts| |
------|--------|--------|-----|--------------|----------|-------------|
A |N.h.h.h | ALL | 0 | 1.0.0.0 | 24/7 | 16,777,214 |
| | ACCEPT | | to | | |
| | HUGE | | 127.0.0.0 | | |
| | CORPS | | | | |
-----------------------------------------------------------------------
|N.N.h.h | TO ALL | 10 | 128.1.00 | 16/14 | 65,543 |
B | | LARGE | | to | | |
| | CORPS | | 191.254.00 | | |
-----------------------------------------------------------------------
|N.N.N.h |TO ALOT | 110 | 192.0.1.0 | 8/22 | 254 |
C | |OF | | to | | |
| |SMALL | | 223.225.254 | | |
| |CORPS | | | | |
-----------------------------------------------------------------------
D | NONE |MULTI-CA|1110 | 224.0.0.0 | NOT FOR | UNKNOWN |
| |ST ADDR.| | to | USUAL | |
| |RFC-1112| |239.255.255.255| USE | |
-----------------------------------------------------------------------
E | NOT FOR|EXPERIME|1,1,1,1| 240.0.0.0 |NOT FOR| NOT FOR USE|
| USE |NTAL | | to |USE | |
| |ADDR. | |254.255.255.255| | |
-----------------------------------------------------------------------
N=NETWORK , h=HOST .
Notice the address range 127.X.X.X.
These addresses are assigned to internal use to the network device, and are
used as an application tool only. For example: 127.0.0.1, the most common one,
is called the loopback address - everything sent here goes directly back to
you, without even traveling out on the wire.
Also, some IPs are reserved for VPNs - Virtual Private Networks. These are
local area networks over wide area networks that use the Internet Protocol to
communicate, and each computer inside the network is assigned with an IP
address. So, suppose a certain computer wants to send a data packet to
another host on the network with the IP 'x', but there's also another host on
the Internet that has the same IP - what happens now? So this is why you
cannot use these and other forms of reserved IPs on the Internet.
---.---.---.---
^ ^
| |
network | host
Every " --- " = 8 bits.
The first bits ===> network address
The last bits ===> host address.
with 8 bits you can present from 0-255 . (binary=(2 to the power of 8)-1)
Example:
11000010.01011010.00011111.01001010 (binary)
194.90.31.74 (decimal)
IP address CLASSES :
We can classify IP addreses to 5 groups. You can distinguish them by comparing the "High Order" bits (the first four bits on the
left of the address):
type | model | target | MSB |addr.range |bit number| max.stations|
| | groups | | |net./hosts| |
------|--------|--------|-----|--------------|----------|-------------|
A |N.h.h.h | ALL | 0 | 1.0.0.0 | 24/7 | 16,777,214 |
| | ACCEPT | | to | | |
| | HUGE | | 127.0.0.0 | | |
| | CORPS | | | | |
-----------------------------------------------------------------------
|N.N.h.h | TO ALL | 10 | 128.1.00 | 16/14 | 65,543 |
B | | LARGE | | to | | |
| | CORPS | | 191.254.00 | | |
-----------------------------------------------------------------------
|N.N.N.h |TO ALOT | 110 | 192.0.1.0 | 8/22 | 254 |
C | |OF | | to | | |
| |SMALL | | 223.225.254 | | |
| |CORPS | | | | |
-----------------------------------------------------------------------
D | NONE |MULTI-CA|1110 | 224.0.0.0 | NOT FOR | UNKNOWN |
| |ST ADDR.| | to | USUAL | |
| |RFC-1112| |239.255.255.255| USE | |
-----------------------------------------------------------------------
E | NOT FOR|EXPERIME|1,1,1,1| 240.0.0.0 |NOT FOR| NOT FOR USE|
| USE |NTAL | | to |USE | |
| |ADDR. | |254.255.255.255| | |
-----------------------------------------------------------------------
N=NETWORK , h=HOST .
Notice the address range 127.X.X.X.
These addresses are assigned to internal use to the network device, and are
used as an application tool only. For example: 127.0.0.1, the most common one,
is called the loopback address - everything sent here goes directly back to
you, without even traveling out on the wire.
Also, some IPs are reserved for VPNs - Virtual Private Networks. These are
local area networks over wide area networks that use the Internet Protocol to
communicate, and each computer inside the network is assigned with an IP
address. So, suppose a certain computer wants to send a data packet to
another host on the network with the IP 'x', but there's also another host on
the Internet that has the same IP - what happens now? So this is why you
cannot use these and other forms of reserved IPs on the Internet.
