From Fedora Project Wiki

Avahi is a local dynamic replacement for the DNS system. Its purpose is to provide zero configuration multicast DNS service discovery. Together with nss-mdns it provides .local zeroconf name resolution to applications via NSS.

IPv6 support

Avahi is capable of working on IPv6 addresses and resolving IPv6 name-address mappings. However, IPv6 support is still disabled by default in Fedora. Link-local IPv6 addresses returned from nss-mdns lack scopeid (usually written as interface name after a percent sign) and are therefore unusable.

Fedora Bug 821127 – Avahi's IPv6 support is disabled by default

Fedora Bug 719178 – Applications can't connect to IPv6 link-local addresses learned through nss-mdns and Avahi