May 28, 2020
Thank you for using BIND 9!
BIND is open source software that implements the Domain Name System (DNS) protocols for the Internet. It is a reference implementation of those protocols, but it is also production-grade software, suitable for use in high-volume and high-reliability applications. It is very widely used DNS software, providing a robust and stable platform on top of which organizations can build distributed computing systems with the knowledge that those systems are fully compliant with published DNS standards.
BIND is and will always remain free and openly available. It can be used and modified in any way by anyone.
BIND is maintained by Internet Systems Consortium, a public-benefit 501(c)(3) nonprofit, using a “managed open source” approach: anyone can see the source, but only ISC employees have commit access. In the past, the source could only be seen once ISC had published a release; read access to the source repository was restricted just as commit access was. That has changed, as ISC now provides a public git mirror to the BIND source tree (see below).
At ISC, we’re committed to building communities that are welcoming and inclusive: environments where people are encouraged to share ideas, treat each other with respect, and collaborate towards the best solutions. To reinforce our commitment, ISC has adopted a slightly modified version of the Django Code of Conduct for the BIND 9 project, as well as for the conduct of our developers throughout the industry.
Public BIND releases are always available from the ISC FTP site.
A public-access GIT repository is also available at https://gitlab.isc.org. This repository is a mirror, updated several times per day, of the source repository maintained by ISC. It contains all the public release branches; upcoming releases can be viewed in their current state at any time. It does not contain development branches or unreviewed work in progress. Commits which address security vulnerablilities are withheld until after public disclosure.
You can browse the source online via https://gitlab.isc.org/isc-projects/bind9
To clone the repository, use:
$ git clone https://gitlab.isc.org/isc-projects/bind9.git
Release branch names are of the form
v9_X, where X represents the second number in the BIND 9 version number. So, to check out the BIND 9.12 branch, use:
$ git checkout v9_12
Whenever a branch is ready for publication, a tag is placed of the form
v9_X_Y. The 9.12.0 release, for instance, is tagged as
The branch in which the next major release is being developed is called
Reports of flaws in the BIND package, including software bugs, errors in the documentation, missing files in the tarball, suggested changes or requests for new features, etc., can be filed using https://gitlab.isc.org/isc-projects/bind9/issues.
Due to a large ticket backlog, we are sometimes slow to respond, especially if a bug is cosmetic or if a feature request is vague or low in priority, but we try at least to acknowledge legitimate bug reports within a week.
ISC’s GitLab system is publicly readable; however, you must have an account to create a new issue. You can either register locally or use credentials from an existing account at GitHub, GitLab, Google, Twitter, or Facebook.
If you think you may be seeing a potential security vulnerability in BIND (for example, a crash with REQUIRE, INSIST, or ASSERT failure), please report it immediately by emailing to firstname.lastname@example.org. Plain-text e-mail is not a secure choice for communications concerning undisclosed security issues so please encrypt your communications to us if possible, using the ISC Security Officer public key.
Do not discuss undisclosed security vulnerabilities on any public mailing list. ISC has a long history of handling reported vulnerabilities promptly and effectively and we respect and acknowledge responsible reporters.
ISC’s Security Vulnerability Disclosure Policy is documented at https://kb.isc.org/docs/aa-00861.
If you have a crash, you may want to consult “What to do if your BIND or DHCP server has crashed.”
BIND is licensed under the Mozilla Public License 2.0. Earlier versions (BIND 9.10 and earlier) were licensed under the ISC License
ISC does not require an explicit copyright assignment for patch contributions. However, by submitting a patch to ISC, you implicitly certify that you are the author of the code, that you intend to relinquish exclusive copyright, and that you grant permission to publish your work under the open source license used for the BIND version(s) to which your patch will be applied.
Patches for BIND may be submitted directly via merge requests in ISC’s GitLab source repository for BIND.
Patches can also be submitted as diffs against a specific version of BIND – preferably the current top of the
main branch. Diffs may be generated using either
git format-patch or
Those wanting to write code for BIND may be interested in the developer information page, which includes information about BIND design and coding practices, including discussion of internal APIs and overall system architecture.
Every patch submitted is reviewed by ISC engineers following our code review process before it is merged.
It may take considerable time to review patch submissions, especially if they don’t meet ISC style and quality guidelines. If a patch is a good idea, we can and will do additional work to bring it up to par, but if we’re busy with other work, it may take us a long time to get to it.
To ensure your patch is acted on as promptly as possible, please:
make checkto ensure your change hasn’t caused any functional regressions.
If you need to make changes to
configure, you should not edit it directly; instead, edit
configure.in, then run
autoconf. Similarly, instead of editing
config.h.in directly, edit
configure.in and run
When submitting a patch as a diff, it’s fine to omit the
configure diffs to save space. Just send the
configure.in diffs and we’ll generate the new
configure during the review process.
All functional changes should be documented. There are three types of documentation in the BIND source tree:
.rst: for example, the
namedman page is
doc/arm/; the PDF and HTML versions are automatically generated from the
Patches to improve existing documentation are also very welcome!
BIND is a large and complex project. We rely heavily on continuous automated testing and cannot merge new code without adequate test coverage. Please see the “Testing” section of doc/dev/dev.md for more information.
Thank you for your interest in contributing to the ongoing development of BIND 9.