Usable IPv4/IPv6 addresses
February 27, 2008
Though you can assign your interface arbitrary addresses, Linux refuses to route certain subnets. “Consider all addresses with the first three bits different of 000 and 111 as unicasts.” is a comment in the code that needs a bit of thought, conveniently, 2000::/16 – DFFF::/16 is usable, as is still the deprecated FEC0::/16 region.
Update July 22 2009: One can use fc00::/7 for site-local things.
