What Are ISP Subnet Proxies? A Guide to /24 Proxy Blocks
Team CleanProxiesMost proxy plans hand you a list of individual IPs. A subnet plan hands you entire blocks of consecutive addresses instead. For large teams, that difference changes how you manage risk, routing and cost.
What is a subnet?
IP addresses are allocated in blocks. A /24 subnet (said "slash twenty-four") is a block of 256 consecutive IPv4 addresses that share their first three numbers — for example everything from 203.0.113.0 to 203.0.113.255. After setting aside reserved addresses, a /24 gives you roughly 255 usable proxies.
Websites and anti-fraud systems often reason about whole subnets, not just single IPs. If enough addresses in a /24 misbehave, the entire block can be rate-limited or blocked at once.
How ISP subnet proxies work
ISP Subnet Proxies are static ISP proxies sold by the block. Like regular ISP proxies, each address is registered to a real Internet Service Provider and stays the same for as long as it's on your plan. The difference is that you receive complete /24 ranges dedicated to you, available in sizes of one, two or four subnets (255, 510 or 1,020 IPs).
Why buy whole subnets?
You control the neighbourhood. When you share a /24 with other customers, their behaviour affects the block's reputation. With a dedicated subnet, every address in it is yours, so its reputation is too.
Cleaner segmentation. Assign one subnet per client, project or platform. If a target restricts one block, your other work keeps running on unaffected ranges.
Easier allow-listing. Partners and internal firewalls can allow an entire range in one rule instead of hundreds of individual addresses.
Lower cost per IP. Buying in blocks is the cheapest way to get large numbers of static ISP IPs — see the pricing page for current rates.
Subnet diversity: single block or several?
If a website blocks at the subnet level, every IP you have in that block is affected together. Spreading the same number of IPs over several subnets — and several providers — limits the impact of any one block:
| Setup | Strength | Risk |
|---|---|---|
| One /24 | Simple to manage and allow-list | One block decision affects everything |
| Several /24s, one provider | Easy segmentation by project | Shared provider-level signals |
| Several /24s, several providers | Maximum resilience | More ranges to track |
Who are subnet proxies for?
Agencies and resellers who segment work by client.
Data teams running large, steady web scraping or AI training data collection on static IPs.
E-commerce and social media operations managing hundreds of accounts that each need a stable, dedicated address.
If you need fewer than a couple of hundred IPs, regular ISP proxies are more flexible — you can buy exactly the quantity you need and add more any time.
Frequently Asked Questions
A /24 contains 256 addresses. Our subnet plans count 255 usable proxy IPs per /24, sold as one, two or four subnets (255, 510 or 1,020 IPs).
No. The subnets on an ISP Subnet plan are dedicated to your account for as long as the plan is active.
Both are static IPs registered to real ISPs. ISP proxies are sold individually in any quantity; ISP subnet proxies are sold as complete /24 blocks, which gives you control over the whole range and the lowest price per IP.
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