{"abstract":"Ipv4 network broadcast address is not allocated to host.","category":"Network routing","checks":4,"contract":"Bounded offline decision model: ipv4 network broadcast address is not allocated to host. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","contract_signature":"address, network","evaluation_group":"xh-ipv4-network-broadcast-address-is-not-allocated-to-host","failed_approach":"The attempted repair uses `ipaddress.ip_address(address) != ipaddress.ip_network(network).broadcast_address` and still violates a separate fixture.","family":"xh-ipv4-network-broadcast-address-is-not-allocated-to-host","id":"FA-7171","implementations":{"attempt":{"sha256":"0ba0a6b6e07b3cc805ca93da539ebf4b7a88ba0eae94b73c578c46ab1d93b3df","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(address, network):\n    return ipaddress.ip_address(address) != ipaddress.ip_network(network).broadcast_address\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('192.0.2.255', '192.0.2.0/24'), False)\", \"check('fixture 2', solve('192.0.2.0', '192.0.2.0/24'), False)\", \"check('fixture 3', solve('192.0.2.1', '192.0.2.0/24'), True)\", \"check('fixture 4', solve('192.0.3.1', '192.0.2.0/24'), False)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"4b39b98903e45eadd6992c2f32d4169133492849573b3fd0640c8800706ced07","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(address, network):\n    return ipaddress.ip_address(address) in ipaddress.ip_network(network)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('192.0.2.255', '192.0.2.0/24'), False)\", \"check('fixture 2', solve('192.0.2.0', '192.0.2.0/24'), False)\", \"check('fixture 3', solve('192.0.2.1', '192.0.2.0/24'), True)\", \"check('fixture 4', solve('192.0.3.1', '192.0.2.0/24'), False)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"xh-ipv4-network-broadcast-address-is-not-allocated-to-host","generated_at":"2026-09-29T14:38:09.105044+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic network routing model isolates the ipv4-network-broadcast-address-is-not-allocated-to-host policy at a network component boundary.","root_cause":"The faulty implementation uses `ipaddress.ip_address(address) in ipaddress.ip_network(network)` for the ipv4-network-broadcast-address-is-not-allocated-to-host decision.","sha256":"91be7497a6e2c6784a1cd9714bdde375f9dec01e65302d662378efdb0fb0968c","title":"Ipv4 network broadcast address is not allocated to host · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":49.459,"exit_code":1,"observations":[{"actual":true,"check":"fixture 2","expected":false,"passed":false},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":true,"check":"fixture 4","expected":false,"passed":false},{"actual":false,"check":"fixture 1","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":48.701,"exit_code":1,"observations":[{"actual":true,"check":"fixture 2","expected":false,"passed":false},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":true,"check":"fixture 1","expected":false,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": true, \"expected\": false, \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}