IPv6 autoconf addresses with changing RAs...

[Eugene M. Kim]

I guess the proper way would be rtadvd's prefix lifetime configuration 
(maxinterval, pltime and vltime).  I set it to maxinterval#20, 
pltime#90, vltime#130.  You *must* also delete old prefixes from the 
internal interface(s), or rtadvd will continue advertising them because 
it will think those old prefixes are still valid.

One caveat is, though, you can't let rtadvd pick all the prefixes from 
internal interfaces (i.e. those that don't have rltime#0 specified), 
because that way rtadvd uses default parameters (maxinterval#30, 
pltime#86400, vltime#259200) for the prefixes it picked up; this is too 
long.  Specifying pltime/vltime without an addr directive seems to have 
no effect (contrary to what the example in rtadvd.conf(5) suggests).  
You have to automatically regenerate rtadvd.conf from the 
linkup/linkdown scripts to specify/remove the 6to4 prefixes calculated 
then SIGHUP the rtadvd.  I wonder if the latest KAME version of rtadvd 
has any solution to this problem.

/me looks in the general direction of Umemoto-san ^^

Eugene