# mschwager/fierce

A DNS reconnaissance tool for locating non-contiguous IP space.

Repository: https://github.com/mschwager/fierce
Canonical: https://ross.abutalabs.com/products/fierce
Language: Python
License: GPL-3.0
License Family: copyleft
Topics: dns, zone-transfers, reconnaissance, discovered-domains, name-server, domain, subdomain, fierce
Last push: 2024-08-28T14:35:58+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 3781, "days_push": 735, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1808, forks 215 (observed 2026-08-28T04:05:39.235904+00:00)

## What it is
Fierce is a Python 3 DNS reconnaissance tool that locates non-contiguous IP space and hostnames for specified domains. It enumerates subdomains, attempts zone transfers, and traverses nearby IPs to find contiguous blocks, serving as a precursor to scanners like nmap.

## Use cases
- enumerate subdomains for a target domain
- attempt DNS zone transfers during a pentest
- find non-contiguous IP space belonging to a company
- discover misconfigured networks leaking internal address space
- pre-scan reconnaissance before running nmap
- find nearby contiguous IP blocks around discovered hosts

## When to choose
- you need lightweight DNS-based reconnaissance before port scanning
- you want to check domains for zone transfer vulnerabilities
- you're doing OSINT or authorized security assessments on a domain

## When to avoid
- you need full port scanning or vulnerability exploitation (use nmap, nessus)
- you need broad internet-wide scanning
- you lack authorization to test the target domain

## Facets
- artifact type: cli-tool
- maturity: active
- function: security, networking, search-engine
- domain: security, networking, penetration-testing
- platform: windows, python, cli
- tags: dns-reconnaissance, zone-transfer, subdomain-enumeration, osint, pentest, command-line, linux, macos

## Member repositories
- mschwager/fierce (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:39.235904+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:21:23.172315+00:00, confidence not recorded.
  - readme: https://github.com/mschwager/fierce (fetched 2026-08-28T04:05:39.235904+00:00, sha 25669e0bef61)
  - registry_pypi: https://pypi.org/pypi/fierce/json (fetched 2026-08-29T11:00:22.209165+00:00, sha 7c0aa07e176a)
- Data as of 2026-08-30T08:39:29.467469+00:00.