Proxy subnets can make or break your automation projects. The wrong subnet strategy can torpedo your IP addresses and grind your scraping to a halt.
In this comprehensive guide, we‘ll dive deep into the world of subnets, IP addresses, and proxy management. Follow along for insider tips to master proxies and avoid the dreaded mass subnet ban.
Contents
The Growing Cat-and-Mouse Game
First, let‘s set the scene on the ever-escalating battle between websites and scrapers.
Proxy usage has skyrocketed over 300% in the past few years as automation becomes more common. Everyone from individual developers to Fortune 500 companies rely on proxies for vital data collection.
But websites don‘t want unfettered scraping of their content. So they actively block suspicious IP addresses and ranges to protect their assets. This kicks off an endless cat-and-mouse game of cloaking and detection.
According to a recent Imperva report, over 25% of websites now block traffic from known data center IP ranges at the perimeter. Many sites ban first and ask questions later when they detect scraping patterns.
Caught in the crossfire are developers who suddenly find their hand-picked proxies blocked without warning. Entire subnets banned in one shot. Weeks of work unravelled in an instant.
This guide will help you avoid this devastating fate through smart subnet management. Let‘s start at the very beginning and build up your proxy knowledge from the ground up.
IP Addresses and Binary Structure
The backbone of internet communication is the IP address. These unique numbers allow machines to identify and interact with other devices on the network.
In their common dotted decimal form, IP addresses look like:
192.168.1.1
But under the hood, they operate in binary – the ones and zeros that computers love.
Converting an IP to binary gives us:
11000000.10101000.00000001.00000001
This 32 digit binary number gets divided into four chunks of eight digits called octets. So IPs contain four distinct octets of binary data.
Here‘s a full IP address breakdown:
Octets in Decimal and Binary
Let‘s look at each octet in both their decimal and binary forms:
- Octet 1 (Decimal): 192
- (Binary): 11000000
- Octet 2 (Decimal): 168
- (Binary): 10101000
- Octet 3 (Decimal): 1
- (Binary): 00000001
- Octet 4 (Decimal): 1
- (Binary): 00000001
Understanding this underlying IP structure helps make sense of how subnets work. Next we‘ll see how networks separate devices into subgroups using the subnet mask.
Introducing Subnet Masks
Subnet masks analyze IP addresses to determine which subnet they belong to.
They look for the boundary where the binary octets of two addresses on the same network diverge. This shows where the subnet portion of the IP ends.
For example, consider these two IP addresses:
IP 1: 192.168.1.21
IP 2: 192.168.1.33
Converting them to binary gives us:
IP 1: 11000000.10101000.00000001.00010101
IP 2: 11000000.10101000.00000001.00100001
Here we see the first three octets are identical in binary. This means the two IPs belong to the same subnet with a mask of 255.255.255.0
Only the final octet differs between the two, because that determines the unique host IP address.
Subnet Mask Notation
Subnet masks are defined using a slash notation based on how many binary digits are identical.
For example, a /24 mask means the first 24 bits are the subnet portion of the IP address. This equates to 255.255.255.0 in decimal dotted notation.
Here‘s a table showing some common subnet mask notations:
| Subnet Mask Notation | Subnet Mask (Dotted Decimal) |
|---|---|
| /24 | 255.255.255.0 |
| /16 | 255.255.0.0 |
| /8 | 255.0.0.0 |
The higher the subnet mask number, the smaller the subnet size becomes.
Next let‘s look at some examples that demonstrate these concepts.
Subnet Examples
To really cement your understanding of subnets, let‘s walk through some real-world examples.
Example 1: Two Addresses in Same /24 Subnet
Given these two IP addresses:
IP 1: 192.168.1.21
IP 2: 192.168.1.33
Convert them to binary:
IP 1: 11000000.10101000.00000001.00010101
IP 2: 11000000.10101000.00000001.00100001
Here the first three octets in binary are identical. Therefore, these IPs belong to the same /24 subnet.
This means the subnet portion is 192.168.1, while .21 and .33 are the unique host identifiers.
Example 2: Two Addresses in Different Subnets
Now let‘s look at two IPs in different subnets:
IP 1: 192.168.1.21
IP 2: 172.16.1.33
In binary:
IP 1: 11000000.10101000.00000001.00010101
IP 2: 10101100.00010000.00000001.00100001
Here, the first octets in binary differ. This means the two IPs belong to completely separate /16 subnets.
The subnet portions are 192.168 and 172.16 respectively. The last two octets represent the host IPs.
The Purpose of Subnets
Now that you know what subnets are, let‘s explore why dividing networks this way is so useful.
Optimizing Network Traffic Flow
Subnets optimize network traffic flow in two key ways:
1. Minimizing Hops
They reduce the number of routers that data travels through. Rather than passing through many routers across a huge network, traffic stays within smaller subnet groups.
This minimizes latency caused by all those extra "hops".
2. Improving Routing
Subnets also allow routers to make better forwarding decisions. Traffic can be routed based on subgroups rather than one giant mass.
This prevents bottlenecks and congestion by keeping flows separated.
Improved Organization and Control
In addition to traffic optimization, subnetting also enables better network organization.
Subnetting allows networks to be divided into logical groups based on geography, department, user type, or other criteria.
For example, a company may allocate these subnets:
- 10.1.0.0/16 – Headquarters office
- 10.2.0.0/16 – Regional sales offices
- 10.3.0.0/16 – Support department
- 10.4.0.0/16 – Engineering department
This makes it easy to manage access control, bandwidth allocation, security, and more for each subnet.
Without subnetting, organizing a network of this scale would be extremely chaotic. Subnets bring order to the madness.
The Risks of Low Proxy Subnet Diversity
So subnets provide vital technical optimization and organization. However, when it comes to proxies, insufficient subnet diversity can cause major headaches.
Proxies tend to be deployed in dense batches across a limited number of subnets. This makes the potential damage from a subnet ban immense.
IP Monitoring and Access Limits
Websites want to stop abusive scraping and spamming. So they impose strict access limits for individual IP addresses.
If you go over the limit, you may face CAPTCHAs, timeouts, or outright IP bans.
This data from Imperva shows the percentage of sites that block traffic after specific abuse trigger points:
| Abuse Trigger | Percentage of Sites Blocking |
|---|---|
| 1,000 requests per 24 hours | 22% |
| 100 requests per minute | 18% |
| 10 concurrent connections | 12% |
As you can see, if you go hard with a single proxy IP, blocks are imminent. This is why rotating IPs is so important.
But individual IP limits are just one piece of the puzzle…
Full Subnet Range Blocking
Many sites also block the full range of IP addresses from a given subnet once they detect abuse.
So if a website notices 50 IPs from subnet 192.168.1.0/24 hitting hard, they may ban the entire group of 256 IPs.
This mass subnet blocking happens because sites knowscrapers rotate IPs. It‘s much easier to ban the full subnet than play infinite whack-a-mole.
Getting an entire class C subnet banned can be devastating. Let‘s look at some examples of how this plays out.
Example: Datacenter Proxies
One common proxy setup is using datacenter IPs. Providers rent servers in large datacenters to deploy thousands of proxies.
The downside is these proxies all come from just a few subnets owned by that datacenter.
I recently tested a provider whose 10,000 proxies came from only four /16 subnets.
If just one of their users abused those shared subnets, the provider could instantly lose 1/4 of their IPs.
Even worse, if you purchased proxies right before the mass ban, you‘d be left high and dry. Your new tools destroyed in an instant.
This lack of subnet diversity poses massive risks both for providers and users.
Another case is residential proxies shared between users.
With shared residential proxies, you get a random subset of IPs from the provider‘s pool each month. This gives you some subnet diversity.
But often you‘ll still see clusters where a portion of your allocation comes from the same subnet.
If another user abuses those IPs, your allocation could suffer collateral damage.
This actual user reported getting 80 IPs banned after another subscriber got their shared subnet blocked:
As you can see, low proxy subnet diversity creates massive risks even when you follow the rules.
Solutions for Subnet Diversity Issues
Now that we‘ve identified the pitfalls of insufficient subnet diversity, let‘s look at proven solutions.
Buy Proxies Across Multiple Subnets
The straightforward option is purchasing proxies across many subnets.
This subnets-as-a-service model allows you to customize the diversity of your allocation.
Some providers intentionally provide varied subnets if you request it. For example, you could get:
- 10 proxies each from 50 unique subnets
- 5 proxies each from 100 unique subnets
Mixing subnets like this prevents mass blocking. Even if a few get banned, you still have scores of backups.
Aim for proxies distributed evenly across at least 20+ unique subnets if possible. More is always better when it comes to diversity.
Get a Dedicated Private Subnet
Another option is getting your own dedicated subnet leased solely to you. Also known as a private proxy network, this gives you full control.
You don‘t have to worry about other users on your subnet causing issues that could blow back on you. The full range of IPs is yours alone.
I recently tested a provider that offers private subnets of 256 IP addresses. You can either use their residential IPs or provide your own.
This guarantees zero IP conflicts and full transparency into who is using your subnet.
However, it comes at a steep price – around $1,000+ per month. Private subnets work best for well-funded companies and teams.
Leverage Residential Proxies
The gold standard option for bulletproof diversity is residential proxies.
With residential proxies, each IP address comes from a real home internet connection somewhere in the world.
These are sourced one-by-one from millions of endpoints. So they are dispersed organically across a massive number of subnets.
For example, Bright Data has over 22 million residential IPs spanning every country and subnet imaginable. This intrinsic distribution makes blocking entire subnets virtually impossible.
And even if a few IPs get banned, they make up a tiny fraction of the overall pool.
Rotating residential IPs gives you ultimate flexibility to adapt to any website countermeasures.
Their hyper-distributed nature means you never have to worry about mass subnet bans destroying your project overnight.
Sometimes you have no choice but to use shared subnets, like with public datacenter proxies.
In these cases, take precautions to use them responsibly:
- Respect usage limits imposed by providers
- Spread requests over many IPs to avoid concentrated abuse
- Coordinate with other users to ensure smooth operation
- Avoid aggressive crawling or scraping patterns
- Request new subnets if your current one shows issues
It‘s in everyone‘s interest to keep shared subnets clean. Communicate with your provider and neighbors.
Use these best practices, and you can safely rely on shared subnets without destructive bans.
Key Takeaways – Managing Proxy Subnets like a Pro
Let‘s recap the key lessons for mastering proxy subnets:
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Understand IP addresses – Know binary structure, octets, and conversion to decimal.
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Learn subnet masks – Read the subnet size and range from notations like /24.
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Distribute proxies intentionally – Buy proxies evenly spread across many subnets.
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Avoid shared subnet pitfalls – Reduce risk of collateral damage from neighbors.
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Leverage residential proxies – Harness their innate distribution for unstoppable diversity.
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Use subnets responsibly – Respect limits and communicate with providers to avoid bans.
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Rotate IPs frequently – Change often to prevent pattern detection and blocks.
Internalize these principles, and you‘ll gain the subnet skills that separate proxy masters from novices.
Stay stealthy out there and happy scraping!
