DnsCore 0.3.12

DNS Core

A lightweight DNS client and server for .NET 8, 9, and 10.

Features

• DNS Client — resolve DNS queries with automatic UDP→TCP fallback, retry with exponential backoff, and configurable timeouts
• DNS Server — handle incoming DNS requests via IDnsServerHandler interface or a simple delegate
• UDP & TCP — full support for both transport protocols
• Hosting integration — AddDns() extensions for Microsoft.Extensions.Hosting
• Typed records — A, AAAA, NS, MD, MF, CNAME, DNAME, SOA, MB, MG, MR, PTR, MINFO, MX, TXT, RP, SRV, and PX (IN class)
• Targets — net8.0, net9.0, net10.0
• Platforms — Linux x64, Linux arm64, Windows x64, Windows arm64, macOS arm64

Getting started

dotnet add package DnsCore

See the client example for querying DNS servers and the server example for handling requests with AddDns().

Limitations

• Names: ASCII only, with dots separating labels. Spaces, backslashes, and escape sequences are unsupported; convert internationalized domains to ASCII (IDNA) before parsing. DNS-SD instance names with spaces or Unicode and SOA/RP mailbox labels containing dots are unsupported. Use ParseHostName or IsHostName when stricter hostname validation is needed.
• Raw records: Unknown types use DnsRawRecord, except unsupported formats that may contain DNS compression pointers (AFSDB, RT, SIG, KEY, NXT, NAPTR), which are rejected. Raw RP and IN-class PX are also rejected; non-IN PX is preserved as opaque data.
• Name compression: Encoding follows each record field’s compression rules. Decoding accepts historical compressed names where applicable, while retaining malformed-name and compression-pointer validation.
• RP: Mailbox and TXT-record name in all DNS classes; root (DnsName.Empty) means no mailbox or no associated TXT data. Wire encoding and decoding only, without automatic TXT lookup. Embedded names are emitted uncompressed.
• PX: RFC 2163 IN-class wire format only; no RFC 822/X.400 conversion or mail-routing behavior. Embedded names are emitted uncompressed.
• DNAME: Encoding and decoding only; no automatic subtree substitution, synthesized CNAMEs, or resolver following.
• Wildcards: Asterisks are literal; wildcard matching and automatic wildcard answers are not provided.