Information Technology Reference
In-Depth Information
For the third octet:
1
1
1
1
0
0
1
0
128
+64
+32
+16
+0
+0
+2
+0 = 242
11110010 = 242
For the four th octet:
0
0
0
0
1
0
1
0
0
+0
+0
+0
+8
+0
+2
+0 = 10
00001010 = 10
The IP address is 110.50.242.10.
IPv4 Address Classes
IPv4 addresses have five classes: A, B, C, D, and E. In classful addressing, the most signifi-
cant bits of the first byte determine the address class of the IP address. Table 8-9 shows
the high-order bits of each IP address class.
Ta b l e 8 - 9
High-Order Bits of IPv4 Address Classes
Address Class
High-Order Bits
A
0xxxxxxx
B
10xxxxxx
C
110xxxxx
D
1110xxxx
E
1111xxxx
*x can be either 1 or 0, regardless of the address class.
Again, the IPv4 Class A, B, and C addresses are unicast addresses. Unicast addresses rep-
resent a single destination. Class D is for multicast addresses. Packets sent to a multicast
address are sent to a group of hosts. Class E addresses are reserved for experimental use.
IANA allocates the IPv4 address space. IANA delegates regional assignments to Regional
Internet Registries (RIR). The five RIRs are
ARIN (American Registry for Internet Numbers)
RIPE NCC (Reseaux IP Europeens Network Control Center)
APNIC (Asia Pacific Network Information Center)
LACNIC (Latin America and Caribbean Network Information Center)
AfriNIC (African Network Information Centre)
 
 
Search WWH ::




Custom Search