{"id":24079993,"url":"https://github.com/lukateras/subnetgen","last_synced_at":"2025-10-28T06:40:43.941Z","repository":{"id":137034796,"uuid":"200541881","full_name":"lukateras/subnetgen","owner":"lukateras","description":"Random local IPv4/IPv6 ULA subnet generator","archived":false,"fork":false,"pushed_at":"2024-12-27T03:06:32.000Z","size":10,"stargazers_count":0,"open_issues_count":0,"forks_count":0,"subscribers_count":2,"default_branch":"trunk","last_synced_at":"2025-02-22T01:35:11.412Z","etag":null,"topics":["c","cidr","ipv4","ipv6","meson","ula"],"latest_commit_sha":null,"homepage":"","language":"C","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"cc0-1.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/lukateras.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"COPYING","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null}},"created_at":"2019-08-04T21:09:47.000Z","updated_at":"2024-12-27T03:06:35.000Z","dependencies_parsed_at":"2023-04-28T07:27:19.589Z","dependency_job_id":null,"html_url":"https://github.com/lukateras/subnetgen","commit_stats":null,"previous_names":["yanalunaterra/subnetgen","yanalunaterra-wip/subnetgen","yanateras/subnetgen","lukateras/subnetgen"],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lukateras%2Fsubnetgen","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lukateras%2Fsubnetgen/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lukateras%2Fsubnetgen/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lukateras%2Fsubnetgen/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/lukateras","download_url":"https://codeload.github.com/lukateras/subnetgen/tar.gz/refs/heads/trunk","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":240953479,"owners_count":19884024,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["c","cidr","ipv4","ipv6","meson","ula"],"created_at":"2025-01-09T22:40:27.455Z","updated_at":"2025-10-28T06:40:38.922Z","avatar_url":"https://github.com/lukateras.png","language":"C","funding_links":[],"categories":[],"sub_categories":[],"readme":"# subnetgen\n\nTool to generate IPv4 and IPv6 subnetworks.\n\nRationale is to make sure networks are composable, allowing to use more than\none network while keeping every peer addressable.\n\nIPv6 subnetworks are [RFC 4193][] ULA conformant.\n\n[RFC 4193]: https://tools.ietf.org/html/rfc4193\n\nRandomness is taken from `getentropy(3)`. At the moment of writing,\nthis API is only natively supported in Fuchsia, Linux and OpenBSD.\nCompatiblity shim is provided for [Windows](getentropy_windows.h).\n\n| Network | Flag | N, 50% collision chance |     Network capacity |\n| ------- | ---- | ----------------------- | -------------------- |\n| IPv4    | `-4` |                     300 |                  254 |\n| IPv6    | `-6` |               1 230 000 | more than septillion |\n\nAs you can see, generated IPv4 networks provide very limited capacity. You can\ntrade some uniqueness for more peers by decrementing CIDR prefix: refer to\n[CIDR.xyz](https://cidr.xyz).\n\nFlags are processed in order and can be repeated. For example, `subnetgen -44664`\nwill print two IPv4 subnets, then two IPv6 subnets, and then one more IPv4 subnet,\nin that order, each on separate line.\n\nIf you want to calculate chance of collision, refer to [birthday problem][].\n\n[birthday problem]: https://en.wikipedia.org/wiki/Birthday_problem\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flukateras%2Fsubnetgen","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Flukateras%2Fsubnetgen","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flukateras%2Fsubnetgen/lists"}