local is a pseudo-top-level domain used in multicast domain name service (mDNS) of zero configuration networking discovery protocols.

Apple's Bonjour implements mDNS, as does Avahi. If a computer running Mac OS X is not assigned a domain name, it identifies itself as hostname.local.

Name resolution issues may arise if multicast DNS software is used in conjunction with a network that implements the local toplevel DNS domain.

Despite not being a valid top-level domain in the Internet, considerable DNS traffic that queries the local domain exists in the public Domain Name System.^[1] In June 2009, the L root server received more than 400 such queries per second,^[2] ranking 4th in DNS traffic of all TLDs after COM, ARPA, and NET.

References

ca:.local da:.local es:.local it:.local hu:.local no:.local ru:.local sv:Toppdom n