OSPF network type and BFD

Hi fellas,

I am doing OSPF labs and found a peculiar thing . I have two 3560 switches
connected to each other SW1---------------Sw2 back to back . the two fast
ethernet links are running OSPF and i enable network type as point-to-point
on SW1 and broadcast on SW2. I find it really puzzling to se that they
formed neighborship but they r not exchanging their databases. I heard in
one of the Brians INE ATC which says that the compatible network types are

Point to point-----point to point
Point to point ---point to multipoint
point to mulitpoint-----point to multipoint

Broadcast--Broadcast
Broadcast---NonBroadcast
NonBroadcast-----NonBroadcast

But here i can see that a point to point network type can form neighborship
with the broadcast network type .But they not exchanging the routes I am not
able to reach SW1 loopback from SW2 even though SW1 is advertising its
loopback in OSPF. I want to know the LOGIC behind it .? they r forming
neighborship but they are not exchanging routes? How is this possible?

And also in which OSPF packet type they will exchange the NETWORK TYPES of
both switches and how the OSPF running switches comes to now about the
other sides network Type.

2... My second questions is about BFD.. What purpose does BFD solve. I know
that Fibre links has an inbuilt mechanism of checking whether the
bidrectional connection is up or not by using light frequencies for every 50
ms. But Ethernet has a fundamental flaw of not checking the bidirectional
flow of traffic. It just checks the integrity of the electrical pulses of
the interface connection to the link by using their own keepalives . My
questions is BFD functions in only Ethernet interfaces or else what problem
does BFD solve in this real time world?

-- 
With Warmest Regards,
CCIE KID
CCIE#29992 Security
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