v6 peering at PAIX/Palo Alto

[Joe Abley]

Switch and Data recently started distributing addresses assigned out  
of 2001:540:d::/48 for use in v6 peering on their Bay Area fabric  
(exposed at 529 Bryant/Palo Alto, 200 Paul/San Francisco, etc),  
replacing the 6bone prefix that had been in use there for a long time.

Trouble is S&D didn't specify a prefix length when they told people  
their addresses. I know some people who have assumed a /64. S&D  
themselves insist that the correct prefix length is a /48.

Seems to me that if I was S&D, I'd be carving one /64 out of that /48  
for each exchange point fabric I operated. Perhaps they have other  
plans, though (or aspirations to attract more than 2^64 peers to  
their Bay Area fabric :-)

So anyway, just interested -- how many people here assumed that the  
prefix length was /64?

What operational damage might result from a mixture of routers  
configured with their PAIX address variously in a /48 or a /64? Will  
it make any practical difference to anything?