Zero Configuration Networking - Name Resolution

Name Resolution

In 2000, Bill Manning and Bill Woodcock described the Multicast Domain Name Service which spawned the implementations by Apple and Microsoft. Both implementations are very similar. Apple's Multicast DNS (mDNS) is an open specification, while Microsoft's Link-local Multicast Name Resolution (LLMNR) is little used and the specification is not an IETF standards track publication. The latter was published as informational RFC 4795.

The two protocols have minor differences in their approach to name resolution. mDNS allows a network device to choose a domain name in the local DNS namespace and announce it using a special multicast IP address. This introduces special semantics for the local domain, which is considered a problem by some members of the IETF. The current LLMNR draft allows a network device to choose any domain name, which is considered a security risk by some members of the IETF. mDNS is compatible with DNS-SD as described in the next section, while LLMNR is not.