Which of these tables is used by an LSR to perform a forwarding lookup for a packet destined to an address within an RFC 4364 VPN?
A.
CEF
B.
FIB
C.
LFIB
D.
IGP
Explanation:
(Notice: The term Label Switch Router (LSR) refers to any router that has awareness of MPLS labels)Label Forwarding Information Base (LFIB) is responsible for forwarding incoming packets based on label as it holds necessary label information,
as well as the outgoing interface and next-hop information.
IMHO the question is unclear.
The edge LSR would use FIB and others will use LFIB.
“packet destined to an address” suggests that it has no label yet, so B will be the right answer.
For other LSRs the address is irrelevant.