Endeavoury.DNS.Client 1.0.10

DNS.Client

DNS.Client is a dependency-free, wire-compatible DNS resolver library for .NET. It implements the client-side protocol described by RFC 1035, with a modern high-level API for application lookups and a low-level API for protocol work.

Why this package?

• Works on runtimes implementing .NET Standard 2.0 or 2.1.
• Uses UDP by default, retries across resolvers, and falls back to TCP for truncated responses.
• Preserves unknown record types as raw RDATA instead of discarding bytes.
• Supports synchronous and asynchronous APIs, cancellation, timeouts, AXFR, and reverse DNS.
• Includes a TTL-aware LookupClient cache and typed record collection helpers.
• Has no third-party runtime dependencies.

Install

dotnet add package Endeavoury.DNS.Client

A first lookup

using System.Net;
using DNS.Client;

var lookup = new LookupClient();
var response = await lookup.QueryAsync("example.com", QuestionType.A);

foreach (var address in response.Answers.ARecords())
    Console.WriteLine(address.Address);

For deterministic infrastructure or tests, specify resolvers explicitly:

var lookup = new LookupClient(new LookupClientOptions
{
    NameServers = new[] { new NameServer(IPAddress.Parse("1.1.1.1")) },
    Timeout = TimeSpan.FromSeconds(2),
    Retries = 3,
    EnableCache = true
});

Capabilities at a glance

Choose the right API

Documentation

• Usage guide — queries, options, records, cancellation, and examples.
• DNS fundamentals — names, records, recursion, caching, and transport.
• Technical architecture — wire codec, resolver pipeline, and failure handling.
• Record reference — supported types, models, and unknown-record behavior.
• API reference — public types and recommended usage patterns.
• Troubleshooting — timeouts, truncation, NXDOMAIN, and package diagnostics.
• Contributing — local development, tests, style, and pull requests.
• Publishing — semantic versions, GitHub Releases, and Trusted Publishing.

Coverage and RFC compliance

Every CI build runs the complete test suite with Coverlet and publishes a Cobertura coverage artifact. Open the CI workflow, select a successful run, and download code-coverage-* to inspect line and branch coverage. Coverage is measured from the DNS.Client assembly only; tests and generated code are excluded. A numeric badge will be added once a stable coverage service is configured for this repository.

RFC status is tracked explicitly in the RFC compliance matrix. The current implementation is a hardened unicast stub resolver: classic DNS message encoding/decoding, unknown-record round trips, UDP/TCP fallback, retries, AXFR, and modern core record models are covered. EDNS, DNSSEC validation, encrypted transports, SVCB/HTTPS, mDNS, dynamic update, and other optional ecosystems remain marked MISSING or NOT_APPLICABLE until implemented and tested.

Project layout

DNS.Client/             Library source
DNS.Client.Tests/       Protocol and transport tests
DNS.Client.Console/     Small command-line example
docs/                   Developer and protocol documentation
.github/workflows/      Build, test, release, and package publishing

Compatibility and security

The library targets .NET Standard 2.0 and 2.1 and does not execute code received from DNS servers. DNS answers are untrusted input: validate names and record content before using them in security-sensitive decisions. Classic DNS provides no confidentiality or authenticity; use a trusted transport or DNSSEC-aware infrastructure when those properties are required.

License

Released under the MIT License.