Understanding the 10.110.88.0/21 IP Address Block: Role in IP Addressing and Subnetting

In modern computer networking, efficient IP address allocation and routing are paramount. Classless Inter-Domain Routing (CIDR) notation is the standard method for representing blocks of IP addresses and their associated network masks.

This article delves into a specific example, 10.110.88.0/21, exploring its characteristics, how it fits into IP addressing principles, and its role in subnetting, based on detailed network analysis.

The Basics of CIDR Notation [10.110.88.0/21]

Before dissecting 10.110.88.0/21, it’s essential to understand CIDR notation itself. Introduced to overcome the limitations of older classful networking, CIDR uses a format consisting of an IP address followed by a forward slash (/) and a prefix length (e.g., /21). This prefix length is crucial; it indicates the number of leading bits in the 32-bit IPv4 address that represent the network portion. These bits must be identical for all devices within that specific network block. The remaining bits identify individual hosts within the network.

The prefix length directly corresponds to the subnet mask. A prefix length of ‘/n’ means the first ‘n’ bits of the subnet mask are ‘1’s, and the remaining ’32-n’ bits are ‘0’s. This mask effectively separates the network part from the host part of an IP address. For example, the common /24 prefix equates to a 255.255.255.0 subnet mask, where the first 24 bits define the network.

Table of Contents

Deconstructing the 10.110.88.0/21 Block

The notation 10.110.88.0/21 represents a specific block of IPv4 addresses. Let’s break it down:

Network Address (10.110.88.0): This is the first address in the block and serves as the identifier for this particular network segment.
Prefix Length (/21): This indicates that the first 21 bits of any IP address within this block are designated as the network portion. The remaining bits (32 – 21 = 11 bits) are available for identifying hosts within this network.

Determining the Subnet Mask: The /21 prefix length directly translates to a subnet mask. It means the mask has 21 consecutive ‘1’ bits followed by 11 ‘0’ bits:

Binary: 11111111.11111111.11111000.00000000
Dotted Decimal: Converting each 8-bit octet gives 255.255.248.0.

Therefore, the subnet mask for the network 10.110.88.0/21 is 255.255.248.0. This mask allows devices within the network to differentiate their local network segment from others.

Key Characteristics Summary:

Parameter	Value
Network Address	10.110.88.0
Prefix Length	/21
Subnet Mask	255.255.248.0

Calculating the Address Space for 10.110.88.0/21

The size of the 10.110.88.0/21 block is determined by the number of bits available for hosts.

Host Bits: 32 (total IPv4 bits) – 21 (network bits) = 11 host bits.
Total IP Addresses: The number of unique combinations with 11 bits is 211 = 2048. The 10.110.88.0/21 block contains a total of 2048 IP addresses.
Usable IP Addresses: Within any IP block, two addresses are reserved:
- The first address (10.110.88.0) is the Network Address.
- The last address is the Broadcast Address. Therefore, the number of addresses available for assignment to devices (usable IPs) in the 10.110.88.0/21 block is 2048 – 2 = 2046.

Network and Host Boundaries within 10.110.88.0/21

The /21 prefix explicitly defines the boundary: the first 21 bits identify the network, and the last 11 bits identify the host. All 2048 addresses within 10.110.88.0/21 share the same initial 21 bits.

Let’s look at key addresses in binary (Network | Host):

Network Address (10.110.88.0): 00001010.01101110.01011 | 000.00000000 (Host bits are all zeros)
First Usable IP (10.110.88.1): 00001010.01101110.01011 | 000.00000001 (Smallest non-zero host value)
Last Usable IP (10.110.95.254): 00001010.01101110.01011 | 111.11111110 (Largest host value before all ones)
Broadcast Address (10.110.95.255): 00001010.01101110.01011 | 111.11111111 (Host bits are all ones)

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Usable IP Address Range Summary:

Address Type	IP Address
Network Address	10.110.88.0
First Usable IP	10.110.88.1
Last Usable IP	10.110.95.254
Broadcast Address	10.110.95.255

The range of addresses encompassed by 10.110.88.0/21 is from 10.110.88.0 to 10.110.95.255.

Subnetting the 10.110.88.0/21 Block

While 10.110.88.0/21 defines a network with 2046 usable IPs, it can be further divided into smaller network segments through subnetting. This is done by “borrowing” bits from the available 11 host bits and adding them to the network portion.

Trade-off: Borrowing ‘n’ host bits creates 2n subnets, but reduces the number of hosts available in each new, smaller subnet.

Example: Subnetting 10.110.88.0/21 to support ~500 hosts per subnet. To get ~500 usable addresses, we need 9 host bits (29 – 2 = 510 usable IPs). Since 10.110.88.0/21 has 11 host bits, we borrow 11 – 9 = 2 bits for subnetting.

Number of subnets created: 22 = 4 subnets.
New prefix length: 21 (original) + 2 (borrowed) = /23.
New subnet mask: 255.255.254.0.

Subnetting Options for 10.110.88.0/21:

Borrowed Host Bits	New Prefix Length	Subnet Mask	Number of Subnets	Usable Hosts per Subnet
1	/22	255.255.252.0	2	1022
2	/23	255.255.254.0	4	510
3	/24	255.255.255.0	8	254
4	/25	255.255.255.128	16	126
5	/26	255.255.255.192	32	62
6	/27	255.255.255.224	64	30
7	/28	255.255.255.240	128	14
8	/29	255.255.255.248	256	6
9	/30	255.255.255.252	512	2
10	/31	255.255.255.254	1024	0*

(Note: /31 is often used for point-to-point links with specific RFC standards allowing 2 addresses.)

Subnetting provides benefits like improved network organization, enhanced security through segmentation, efficient IP address use, and better performance by reducing broadcast domain sizes.

Role as a Private IP Address Range

RFC1918 defines specific IP address ranges reserved for private networks, not routable on the public internet. These are:

10.0.0.0/8 (10.0.0.0 to 10.255.255.255)
172.16.0.0/12 (172.16.0.0 to 172.31.255.255)
192.168.0.0/16 (192.168.0.0 to 192.168.255.255)

The address block 10.110.88.0/21 (covering 10.110.88.0 to 10.110.95.255) falls entirely within the 10.0.0.0/8 private range.

Implications:

Internal Use: 10.110.88.0/21 is intended for use within private organizational networks.
Non-Routable: Addresses in this block cannot be routed directly on the public internet.
NAT Required: For devices using IPs from 10.110.88.0/21 to communicate with the public internet, Network Address Translation (NAT) is necessary. NAT allows multiple private IPs to share one or more public IPs.
Inherent Security: Devices using these private addresses are not directly reachable from the public internet, offering a layer of protection.

Real-World Utilization

CIDR blocks like 10.110.88.0/21 are widely used:

Organizational Networks: A block of this size might be assigned to a department, branch office, or large network segment within a company, often further subnetted internally.
ISP Allocations: While 10.110.88.0/21 is private, ISPs allocate similarly sized public CIDR blocks to business customers needing a range of static public IPs.
Cloud Computing: Cloud providers (AWS, Azure, GCP) use private CIDR blocks like 10.110.88.0/21 to define address spaces for customer Virtual Private Clouds (VPCs) or virtual networks, allowing users to structure their cloud infrastructure.

Conclusion

The IP address block 10.110.88.0/21 represents a segment of the private 10.0.0.0/8 address space, defined by the network address 10.110.88.0 and the subnet mask 255.255.248.0. It contains 2048 total IP addresses, with 2046 usable for host assignment (10.110.88.1 to 10.110.95.254). Its /21 prefix length clearly separates the network and host portions of the addresses within its range.

This block is suitable for moderately large internal networks and can be efficiently subdivided using subnetting principles to meet diverse organizational needs. Understanding CIDR notation and the characteristics of blocks like 10.110.88.0/21 is fundamental to designing, managing, and scaling modern IP-based networks effectively.

Axee Davies

Is a freelance tech writer based in the East Continent, is quite fascinated by modern-day gadgets, smartphones, and all the hype and buzz about modern technology on the Internet. Besides this a part-time photographer and love to travel and explore. Follow me on. Twitter, Facebook Or Simply Contact Here. Or Email: [email protected]

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