Subnet
IntermediateA contiguous block of IP addresses under one administrator — and the unit websites often ban, which is why proxy IPs from one subnet share one fate.
In depth
A subnet is a contiguous range of IP addresses grouped under a common network prefix, written in CIDR notation: 203.0.113.0/24 means the 256 addresses sharing the first 24 bits. Subnets are how the internet organizes address space — and how defenders organize their bans.
Why subnets matter for proxy users
Websites rarely ban misbehaving IPs one at a time. Seeing abuse from several addresses in 203.0.113.0/24, a defender simply blocks the whole /24 — 256 IPs gone in one rule, including yours, even if your specific address did nothing wrong. Datacenter proxy packages are especially vulnerable: a provider's "500 IPs" drawn from two adjacent subnets are, from the defender's perspective, two block rules away from worthless.
Judging subnet diversity
- Ask how many distinct subnets (and ASNs) a package spans, not just how many IPs it contains.
- Residential pools win here naturally: their IPs scatter across thousands of consumer ISP ranges, making wholesale blocking impractical without collateral damage to real users.
- IPv6 changes the unit: defenders typically treat each /64 as one household, so a million IPv6 addresses inside one /64 offer no more diversity than a single IPv4 address.
Buying tip
For datacenter proxies, subnet spread is a better quality signal than IP count. Fifty IPs across fifty subnets survive longer than five hundred across two.
Examples
- A defender blocks 198.51.100.0/24 after abuse from a dozen of its addresses, killing every proxy in that range.
- A proxy buyer compares packages by distinct /24 count rather than raw IP count.
- An anti-bot system treats an entire IPv6 /64 as a single visitor for rate-limiting purposes.
Common use cases
FAQs
It's CIDR notation: the first 24 bits of the address are the fixed network prefix, leaving 8 bits — 256 addresses — inside the block. Smaller suffix numbers mean bigger blocks: a /16 holds 65,536 addresses.
They probably shared a subnet. Defenders ban ranges, not just individual IPs, so a package concentrated in one or two blocks can be wiped out by a single firewall rule. Subnet-diverse packages avoid this failure mode.
Far less. Residential IPs are scattered across consumer ISP ranges shared with millions of real customers, so blocking their subnets would lock out legitimate users — exactly the collateral damage most websites can't accept.