DNS Name Resolution

ENSv2 supports resolving traditional DNS domain names (like .com, .xyz) through the ENS protocol. This builds on the DNS on ENS functionality from ENSv1, replacing the single OffchainDNSResolver (ENSIP-17) with a pipeline of three specialized contracts.

Users don't interact with these contracts directly. The Universal Resolver V2 handles the entire flow transparently. This page explains what happens internally and how to configure DNS records for ENS resolution.

How It Works

When the Universal Resolver encounters a DNS name (e.g., example.com), it finds the DNSTLDResolver set as the resolver for that TLD on the root registry. The DNSTLDResolver then follows a multi-step resolution strategy:

Check ENSv1: look for an existing resolver in the ENSv1 registry. If one exists (and it's not the old v1 DNS resolver), delegate to it directly. This preserves backward compatibility.
Query DNSSEC: initiate a CCIP-Read request to fetch DNSSEC-signed TXT records for the domain.
Parse the TXT record: find the first TXT record starting with ENS1, extract the resolver address and context.
Delegate to the parsed resolver: depending on the resolver address, the request is handled by either the DNSAliasResolver (for name rewriting) or the DNSTXTResolver (for inline record data).

TXT Record Formats

To enable ENS resolution for a DNS domain, add a TXT record with the prefix ENS1:

ENS1 <resolver-address-or-name> <context>

The <resolver-address-or-name> can be either a hex address (0x1234...) or an ENS name that resolves to the resolver contract. The <context> depends on which resolver is used.

Inline Records (DNSTXTResolver)

Set the resolver to the DNSTXTResolver address and encode records directly in the context. Multiple records are separated by spaces:

ENS1 dnstxt.ens.eth a[60]=0x1234... t[avatar]=https://example.com/pic.png

Supported record formats:

Prefix	Record type	Example
`a[60]`	Ethereum address (ENSIP-1)	`a[60]=0x1234...`
`a[e0]`	Default EVM address, any chain (ENSIP-19)	`a[e0]=0x1234...`
`a[e<chainId>]`	EVM chain address by chain ID (ENSIP-19)	`a[e8453]=0x5678...`
`a[<coinType>]`	Non-EVM address by SLIP-44 coin type (ENSIP-9)	`a[0]=0x00...`
`t[key]`	Text record	`t[avatar]=https://...`
`c`	Content hash (ENSIP-7)	`c=ipfs://...`
`xy`	Public key (x,y coordinates)	`xy=0x...,0x...`

This is the simplest approach: all record data lives in the DNS TXT record itself, with no on-chain registration required.

Alias Resolution (DNSAliasResolver)

Set the resolver to the DNSAliasResolver address and provide a rewrite rule in the context. Two modes are supported:

Suffix replacement: rewrite the DNS suffix to an ENS suffix.

ENS1 dnsalias.ens.eth com base.eth

This causes sub.example.com to resolve as sub.example.base.eth. The resolver rewrites the suffix, then resolves the rewritten name through the ENSv2 registry hierarchy.

Full replacement: replace the entire name.

ENS1 dnsalias.ens.eth alice.eth

This causes example.com (and all subdomains) to resolve as alice.eth. Useful when you want a DNS domain to mirror an existing ENS name.

Alias resolution is particularly useful for organizations that want their DNS domains to resolve ENS records without on-chain registration of every subdomain.