Question

Problem 1. Network Address

Suppose an ISP has the following IP address block: 130.12.128.0/23

a. Assume that the ISP wants to divide its address block (130.12.128.0/23) into two equal-sized contiguous address blocks, and give one of these address blocks to its customers (C1 and C2). Provide network addresses (of the form a.b.c.d/x) for C1 and C2.

b. Now let’s assume that the ISP wants to divide its address block (130.12.128.0/23) into four equal-sized contiguous address blocks, and give one of these address blocks to its customers (C1, C2, C3, and C4). Provide network addresses (of the form a.b.c.d/x) for each customer.

Answer 1

Sol.

ISP: IP Block address = 130.12.128.0/23

Now if ISP wants divide it into 2 equal size block's then adress space will be follow as:

130.12..128.0/23 = 10000010.00001100.10000000.00000000

Here Underline bits represent the host id bits, so if we want to create block then we need to take the bits from host id part.

So, we will divide like this.

So Range of c1 and c2 will be..

C1 = 130.12.10000000.00000000 => 130.12.128.0 C2 = 130.12.10000001.00000000=> 130.12.129.0

= 130.12.10000000.00000001 => 130.12.128.1 C2 = 130.12.10000001.00000000=> 130.12.129.0

. .

. .

. .

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. .

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= 130.12.10000000.11111111 => 130.12.128.255 , = 130.12.10000001.11111111=> 130.12.129.255

C1 = (130.12.128.0 - 130.12.128.255) 130.12.128.0/24 - 130.12.128.255/24

C2 = (130.12.129.0 - 130.12.129.255)  130.12.129.0/24 - 130.12.129.255/24

Part 2.

Now suppose ISP wants to divide into 4 equal parts.

then It can be divide like this.

C1 = 130.12.128.0 - 130.12.128.127 (130.12.128.0/25 - 130.12.128.127/25)

C2 = 130.12.128.128. - 130.12.128.255 (130.12.128.128/25 - 130.12.128.255/25)

C3 = 130.12.129.0 - 130.12.129.127 (130.12.129.0/25 - 130.12.128.127/25)

C4 = 130.12.129.128 - 130.12.129.255 (130.12.129.128/25 - 130.12.128.255/25)

PLZZZZZZZZZZ UPVOTE FOR MY EFFORTS..