PortSweep.io

Guide

CIDR and scan size

Prefix length is easy to get backwards. Smaller prefix numbers are bigger networks. PortSweep only accepts ranges that are /20 or tighter.

The rule in one sentence

You may scan a /20 or a more specific range (/21/32), or a short list of individual public IPv4 addresses. You may not scan a /19 or anything larger. Private, loopback, and other non-public addresses are not accepted.

CIDRAddressesAllowed?
/198,192No
/204,096Yes — maximum size
/24256Yes — typical LAN-sized public block
/321Yes — a single host

Lists

Paste public IPv4 addresses separated by commas, semicolons, or newlines. Maximum 20 addresses. Larger lists need a support request to robert.lassiter@earnestware.com. Two /24s in one schedule would be 512 hosts and is allowed; two /20s would be 8,192 and is rejected.

Why the cap exists

nmap with version detection is not free in time or bandwidth. A /20 at -T3 -sV is already a serious job. Larger blocks belong in a scoped engagement, not a recurring self-serve report.

Examples the form accepts: 203.0.113.10, 203.0.113.11 or 203.0.113.0/24.