Classful IP Address Tutorial (Interactive Animation 4)

Q1. What is the address of the classification?
Answer: the IP address has been allocated over the domain name and host ID. it shall be classified in 5: (a), (B), (C), (d), (e) the allocation is based on the network mask, the leftmost bits of fixed length are allocated in the network ID and host ID.

Q2. How to classify IP address?
Answer: an IP address is 32 bits (4 bytes), and are often as 4 decimal numbers a.b.c.d bytes per one number. Each number is between 0 ~ 255.They are classified as follows:
Category a: "a" is 0 ~ 127. The domain name is "a" (the leftmost number). "host ID is" b.c.d (3 characters)
Category B: "a" is to 128 ~ 191. the domain name was "a b" (left).Host ID is "c. (d)" (right).
Category C: "a" is to 192 ~ 223.The domain name was "a.b.c" (the leftmost 3 characters). host ID is "d" (rightmost number)
Category (d), (e) "a" is to 224 ~ 255. Class D addresses are used for multicast addresses is assigned to a class E to scientific research.

Q3 how many host symbols and logos for class a, B, and c addresses?
Answer: the host or network marks depends on the number of bytes each.
Class Host IDs network account usage

A very large networks 16,777,216 256

(B) 65 536 65 536 large networks

(C) 256 16,777,216 small systems. contain more than 256 PCs.
Note: when two host for each class is reserved and cannot be set to hosts: all 0 bytes, all 1 bits.

Q4.How to set up categories, when IP addresses are binary?
Answer: we do not only look at the first byte (the leftmost 3 bytes)

To the left of the Leftmost byte of a.b.c. (d) the quantity
Class most bits, binary (4 digits) value

A 1 bit: 0 is 0 ~ 127 0xxxxxxx

(B) 2 bit 10 10xxxxxx 128 ~ 191

(C) 3 bit: 110 110xxxxx is 192 ~ 223
Note: the ratio of the destination network address in the routing table for a classful address is clear companion animation during playback.

Q5. how well a classful address address work?
Answer: It worked well in the early stages when the Internet was not too many computers connected to the Internet, however, the classification of the IP addresses. bit-rate, depending on the length of the networks does not Scale well when the number is increasing.

For example, to configure for 1000 of computers to the network address? class c network is not enough. If class b address space grant for this group, the host IDs are not used by the 64,536. It is high.

To resolve this problem, computer scientists designed classless IP address (or aliverkkoihin) addresses address space can be broken down further into smaller parts. in this way may be too large to fit on the 1000 a group of computers in the network address that contains 1024 hosts.

Classless IP address, see the following tutorial: IP aliverkkoihin.

This is an interactive animation FAQ. Concepts easier to understand when visualizd topology, packets and this animation tables. it appears in the external links section.

IP Addressing Tutorial-Network Address, Mask (Interactive, Visual Animation 3)

Q1. What is network address?
Answer: we are not able to view the network and host addresses in two ways:
1) the domain name and Host-ID

An IP address is made of two components on the left side of the domain name, the right side is the host identifier.

For example, if 100 100.3.4.5 is the domain name, then the host ID for 3.4.5 If 100.3 is the domain name, 4.5 is the host identifier.

2) network address and the host address. see now two examples:

The IP address of the network account the host network address of the host address mask
100.4.5.6/8 100 4.5.6 100.0.0.0 100.4.5.6/8
150.1.2.3 150.1.2.3/16 150.1.0.0 150.1.2.3/16
Note: the network mask is presented as a meal,/m is m 2-digit decimal number between 8 ~ 31.
Note: IP addresses, network and host usually provides.

Q2. constraint properties
The answer to THE IP network mask. use 32-bit IP address for the domain name and host ID to fragment the network address of the domain name bits to the left and right of 0 bytes.

For example, 150.1.2.3/16, for 16 is the network mask 150.1 the network ID, 150.1.0.0/16 is the network address, host ID, 3 2 150.1.2.3/16 is the address of the host address is used for network routers packages.Host address is used to distinguish the isänniltä on the same network.

Q3. Why does the network addresses?
Answer: when the numbers are too many, we use a hierarchical structure to manage them.For example, a structure as a phone number.

For example, there are a number of the people's Republic of China, 086.021.1234.5678 Shanghais. the voice mail message is then switched to the country and city code prefix.Structured telephone numbers are much easier to navigate than flat 10-digit phone numbers.

The Internet is facing a similar situation is almost 4.. 2 billion addresses (IP is 32 bits. or 2 ^ 32 individual addresses.)Routers use the foreword to the packet routing tables.Obviously it is much easier to deal with the systematic addresses as router 4 billion flat ones.

IP solution is to use the network address forward packets, not individual comments. network mask share the address of the network ID and host ID. routing table to network addresses, not IP addresses.

For example,
-Network 100.0.0.0/8 is 16,777,216.The routing table, (100.0.0.0/8, the next-hop interface) says: the same forward packets to the destination network to join the same with the next item.
-Network 150.1.0.0/16 of 65 536. the routing table, (150.1.0.0/16, next-hop interface) to keep passing to 65,536 individual addresses 150.1.0.0/16 on the network.
-Network 150.1.0.0/16 is 65,536 addresses the routing table, (150.1.0.0/16, next-hop interface) to keep passing to 65,536 individual 150.1.0.0/16 network address.
-222.111.44.0/24 256 IP-addresses. the routing table, (222.111.44.0/24, next-hop interface) 256 IP addresses of network 222.111.44.0 nexthop to join forward.

Q4. how this mask digits?
Response., in the same way as To mask the IP address for example.
/8 shall be adopted in accordance with the 255.0.0.0.
/255.255.0.0, shall be adopted in accordance with 16.
/255.255.255.0 is presented as a meal, 24

Q5. Why is the mask length is more than 8 but?
Answer: this is the deal with two types of systems: the IP addresses and Classless. what you are up to now it has a classful address we talked. Classless IP address use any length mask. for more information, see the following tutorials.