All You Need To Know About IP Blocking

What an IP block actually is

A rule that refuses traffic from an address or range. It can be permanent, or — far more often — a temporary throttle that lifts in minutes. Sites use blocks to protect capacity, defend accounts and keep competitors from copying their data wholesale.

The main triggers

Rate. Too many requests in too short a window from one address.

Pattern. Perfectly even timing, alphabetical crawling, no images or CSS fetched — behaviour no human produces.

Reputation. The address already appears on blocklists, or belongs to a hosting ASN the site distrusts by default.

Mismatch. A German IP with an English-US locale, a mobile user agent from a datacenter range, a timezone that doesn't match the country.

Block, throttle or challenge?

Read the response. A 429 with a Retry-After header is a rate limit — slow down and it clears. A 403 on every request from that IP is a block. A captcha or an interstitial is a challenge, meaning the site is unsure rather than hostile. Treating all three the same way is how a temporary slowdown becomes a permanent ban.

Avoiding them

• Spread load across many IPs instead of pushing one harder
• Randomise intervals; add jitter rather than a fixed delay
• Match IP type to the target — residential for consumer sites, datacenter only where it's tolerated
• Keep headers, TLS fingerprint, locale and IP country consistent
• Respect robots.txt and stay on public data
• Cache aggressively so you don't re-request pages you already have

If you're already blocked

Stop the job. Continuing to hammer a blocked address escalates a soft limit into a hard one and can drag the whole subnet with it. Back off, rotate to a clean exit, reduce concurrency, and fix the pattern that caused it — otherwise the new IP burns exactly the same way.