[mpls] validating incoming frames at an Ethernet interface of an LSR

[Anoop Ghanwani <anoop at brocade.com>]

Let's say I have 3 routers R1, R2 & R3 connected
by a layer 2 switch.

Let's say R1 advertises a label, say L1, for a
certain FEC to R2.  Let's assume R1 has a global
LIB (i.e. assigns different labels each time one
is requested).

Now, if R3 sends a frame with L1 addressed to
R1's MAC address, would R1 just pick the frame
up and forward it, or would it actually notice
the problem and drop the frame?

I know we're getting into implementation here,
but would appreciate if someone can point me to
an RFC/draft that discusses this issue.

Thanks,
Anoop