IPv6 addresses and unwanted routing entries

[Chuck Anderson]

On Thu, May 14, 2009 at 01:46:42PM -0400, Neil Horman wrote:
> > 3ffe:ffff:100:f101::/64 dev eth0 metric 256 mtu 1500 advmss 1440  
> > hoplimit 4294967295
> > unreachable 3ffe:ffff::/32 dev lo metric 1024 error -101 mtu 16436  
> > advmss 16376 hoplimit 4294967295

3ffe::/16 is phased out as of June 6, 2006:

http://tools.ietf.org/html/rfc3701

Additionally, 3ffe:ffff::/32 was a "documentation prefix" to be used 
in documentation examples, and hence never used on actual networks.  
Linux is enforcing that with the unreachable route.  Unfortunately, 
all I can find about this is an old expired IETF draft from 2001:

http://www.hexago.com/4105/file.asp?file_id=421
http://mailman.isi.edu/pipermail/6bone/2001-June/004262.html