Question

Aggregate these three address ranges: $$ \begin{aligned} &37.60 .64 .0 / 18 \\ &37.60 .96 .0 / 19 \\ &37.60 .128 .0 / 17 \end{aligned} $$

Short answer

The aggregated address range is 37.60.64.0/17.

Step-by-step solution

Understanding the Address Ranges

First, we need to understand each of the given address ranges: - 37.60.64.0/18: A /18 subnet covers 1024 addresses, with a block size of 64 (6 bits for the host part from 64 in the third octet). - 37.60.96.0/19: A /19 subnet covers 512 addresses, and its block starts from 96, making 32 as its block size (5 bits for hosts). - 37.60.128.0/17: A /17 subnet covers 2048 addresses, with 128 starting the block and the first 7 bits used for routing. The block size is 128.

Finding the Lowest and Highest IP Addresses

To aggregate the ranges, we need to find the lowest starting point and the highest ending point: - Lowest starting point is 37.60.64.0 (from the 37.60.64.0/18 range). - Calculate the end of each range by adding their range size: - 37.60.64.0/18 ends at 37.60.127.255. - 37.60.96.0/19 ends at 37.60.127.255. - 37.60.128.0/17 ends at 37.60.255.255.

Determine the New Subnet Mask

To aggregate them, we should find a common range that encompasses all end ranges, from 37.60.64.0 up to 37.60.255.255. - The total range must start from 64 and extend past 128, hence it can start from 64 with the next higher bit which is 128. - The range defined as 37.60.64.0/17 encompasses all the given address ranges as its maximum address, 37.60.191.255, lies within the given range boundaries.

Simplify and Confirm the Aggregated Range

The aggregated address range is 37.60.64.0 with a subnet mask of /17. This encompasses: - 37.60.64.0 to 37.60.191.255. - Covers all individual ranges without missing any parts. - Ensure by analyzing that each range falls within this larger /17 subnet.

Key concepts

Subnetting

Subnetting is a method used to divide a larger network into smaller, manageable pieces, known as subnets. This technique is crucial in controlling network traffic and improving security. Each subnet operates as its own mini-network, allowing better organization of network resources.
In subnetting, you decide how many hosts (devices) you want in each subnet and how many subnets are needed. This is determined using a subnet mask, which indicates which part of the IP address refers to the network and which part refers to the host. For example:

• A /18 subnet mask means the first 18 bits of the IP address represent the network, leaving 14 bits for hosts.
• A /19 mask leaves 13 bits for hosts.
• A /17 mask has 15 bits for host addresses.

Effective subnetting allows for efficient IP address allocation and reduces overhead in networks.

IP Address Ranges

IP address ranges specify the set of IP addresses assigned to a particular network or subnet. Each range is defined by a start and an end point, determining the possible addresses within. Understanding address ranges is key for network planning and ensuring proper communication within networks.
When you define the start of an address range, you use the network address (e.g., 37.60.64.0). The size of the range is determined by the subnet mask:

• A /18 range includes 1024 addresses.
• A /19 range features 512 addresses.
• A /17 range encompasses 2048 addresses.

The end of each range is calculated based on the size, where the highest possible address forms the end of the range. This helps in organizing and routing traffic efficiently within the network.

CIDR Notation

CIDR, or Classless Inter-Domain Routing, is a standard for specifying IP addresses and their respective network prefixes. It is utilized for allocation of IP addresses and efficient routing. CIDR notation simplifies the representation of IP ranges and improves flexibility compared to older class-based methods.
In CIDR notation, an IP address is expressed along with a suffix indicating the number of bits that form the network part of the address. For example:

• 37.60.64.0/18: This means the first 18 bits are the network part.
• 37.60.96.0/19: Indicates a 19-bit network prefix.
• 37.60.128.0/17: Has a 17-bit network prefix.

This method allows IP addresses to be allocated more smoothly, fitting various sizes of network resources as needed. CIDR helps in avoiding waste of addresses and effectively manages the growth of routing tables on the internet.