## Monday, August 27, 2012

### PowerPoint Presentation On IP Addresses Classless Addressing

PPT On IP Addresses Classless Addressing
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Presentation Transcript:
1.IP Addresses: Classless Addressing

2.VARIABLE-LENGTH BLOCKS
In classless addressing variable-length blocks are assigned that belong to no class. In this architecture, the entire address space (232 addresses) is divided into blocks of different sizes.
The topics discussed in this section include:
Restrictions
Finding the Block
Granted Block

3.Variable-length blocks

4.What is the first address in the block if one of the addresses is 167.199.170.82/27?

5.What is the first address in the block if one of the addresses is 140.120.84.24/20?
Solution Figure 5.3 shows the solution. The first, second, and fourth bytes are easy; for the third byte we keep the bits corresponding to the number of 1s in that group. The first address is 140.120.80.0/20.

6.Find the first address in the block if one of the addresses is 140.120.84.24/20.
Solution The first, second, and fourth bytes are as defined in the previous example. To find the third byte, we write 84 as the sum of powers of 2 and select only the leftmost 4 (m is 4) as shown in Figure 5.4. The first address is 140.120.80.0/20.

7.Find the number of addresses in the block if one of the addresses is 140.120.84.24/20.
Solution The prefix length is 20. The number of addresses in the block is 232-20 or 212 or 4096. Note that this is a large block with 4096 addresses.

8.Using the first method, find the last address in the block if one of the addresses is 140.120.84.24/20.
Solution We found in the previous examples that the first address is 140.120.80.0/20 and the number of addresses is 4096. To find the last address, we need to add 4095 (4096 - 1) to the first address.

9.An organization is granted the block 130.34.12.64/26. The organization needs 4 subnets. What is the subnet prefix length?
Solution We need 4 subnets, which means we need to add two more 1s (log2 4 = 2) to the site prefix. The subnet prefix is then /28.

10.What are the subnet addresses and the range of addresses for each subnet in the previous example?
Solution Figure 5.6 shows one configuration.

11. Thank You.