Two quick questions about the sham-link.
1) Why do we need to use a /32 loopback address to create the sham-link?
2) Why do we need to advertise it to BGP but NOT to ospf. <--This one seems counter-intuitive.
3) How is it that the sham-links can remain Intra-area, even though it's not being advertised into OSPF and being redistributed to the ospf routing domain via redistribution of bgp?