From Fedora Project Wiki

IPv6 support

Please help us to improve Fedora
Please add any package that does not support IPv6 or has problems in dual-stack environment (IPv4 and IPv6) into this tracking bug

Network diagnostics tools

Network diagnostics tools should be updated to query both IPv4 and IPv6 addresses and prefer IPv6 by default, providing switches (e.g. -4 and -6) for IPv4-only and IPv6-only operation.

iputils

The historically IPv4-only commands in iputils package, notably ping and tracepath should support IPv6 right away and should default to dual-stack name resolution and follow operating system's protocol version preference. The ping6 and tracepath6 commands should be obsolete.

System libraries

System libraries should be updated to provide full dual-stack experience.

glibc

The GNU C Library should be updated to support IPv6 link-local addresses in the name service switch.

Client/server software

Packages containing client and server software should be updated to work well in IPv4, IPv6 and dual-stack environments.

DNSSEC

Internationalized domain names

Libraries and tools should be built by default with IDN support.