Internet Assigned Numbers Authority

DNS Service Bindings (SVCB)

Created
2022-05-26
Last Updated
2025-06-18
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Registry Included Below

DNS SVCB Service Parameter Keys (SvcParamKeys)

Expert(s)
Benjamin Schwartz, David Lawrence
Reference
[RFC9460]
Available Formats

CSV
Range Registration Procedures
0-65279 Expert Review
65280-65534 Private Use
Number Name Meaning Change Controller Reference
0 mandatory Mandatory keys in this RR IETF [RFC9460, Section 8]
1 alpn Additional supported protocols IETF [RFC9460, Section 7.1]
2 no-default-alpn No support for default protocol IETF [RFC9460, Section 7.1]
3 port Port for alternative endpoint IETF [RFC9460, Section 7.2]
4 ipv4hint IPv4 address hints IETF [RFC9460, Section 7.3]
5 ech TLS Encrypted ClientHello Config IETF [RFC-ietf-tls-svcb-ech-08]
6 ipv6hint IPv6 address hints IETF [RFC9460, Section 7.3]
7 dohpath DNS over HTTPS path template IETF [RFC9461]
8 ohttp Denotes that a service operates an Oblivious HTTP target IETF [RFC9540, Section 4]
9 tls-supported-groups Supported groups in TLS IETF [draft-ietf-tls-key-share-prediction-01, Section 3.1]
10-65279 Unassigned
65280-65534 N/A Reserved for Private Use IETF [RFC9460]
65535 N/A Reserved ("Invalid key") IETF [RFC9460]