IPv6 is short term for Internet Protocol Version 6. IPv6 is the new generation protocol to succeed the current Internet Protocol version, IP Version 4 (IPv4).
Currently the IPv4 is the most common Internet Protocol and the reason for the new generation Internet Protocol is the shortage of IP version 4 (IPv4) addresses. IPv6 has a larger address space than IPv4. Currently the IPv4 uses 32-bit address whereas the IPv6 uses 128-bit address.
IPv6 fixes a number of problems in IPv4, such as the limited number of available IPv4 addresses. It also adds many improvements to IPv4 in areas such as routing and network auto configuration. IPv6 is expected to gradually replace IPv4, with the two (2) coexisting for a number of years during a transition period.
Linksys devices that support IPv6
Preferring IPv4 over IPv6
Differences between IPv4 and IPv6
Manually enabling IPv6 on Linksys routers