Exam 300-410 topic 1 question 535 discussion

"The non-working state is when R5's LFIB entry for label 16 instructs it to perform a Untagged/No Label operation. Untagged/No Label literally means to strip all of the MPLS labels off the packet and forward the raw IP packet (in this case it's IP). R4 receives a regular IP packet and does a lookup in the FIB." https://www.packetmischief.ca/2015/05/27/mpls-no-label-vs-pop-label/ The first router performs a lookup in LFIB, converts the MPLS packet to IP packet and forwards it to the next hop. Only the next hop performs the FIB lookup.

The mpls router is gonna strip off the mpls label information. Then via the LFIB is gonna sent the packet to the next-hop. The router have this information using the LFIB cause before strip off the mpls packet the router knows where to send it. After that we create a normal packet we are gonna send it to our neighbor router. The other router cause is a normal IP packet is gonna look the FIB table for understand where to send the packet. So answer is C cause we are looking the P router stripping off the label

C is corerct

agree with C, if outbound need to be send untagged, the MPLS part is stripped off

It's B

Key words in this questions are "untagged outgoing labels". So yeah its C

It's about to get forwarded. C is correct.

When an MPLS router receives a packet with an incoming MPLS label and no outgoing label (i.e., an untagged outgoing label), it needs to perform a lookup in the Forwarding Information Base (FIB) to determine the egress interface and next-hop for the packet. The incoming MPLS label is stripped off, and the packet is treated as an untagged packet before performing the FIB lookup. Therefore, option B accurately describes the action performed for untagged outgoing labels in an MPLS router.