Let’s have a look at the label forwarding instance base. The LFIB or the label forwarding instance base is a new table used on routers to forward incoming labeled packets. We used to have the FIB table before and we still have it, which is the forwarding instance base. It’s not the routing table. It’s not the RIB. The routing table is used to store prefixes. It holds information like the prefix, the mask, the outgoing interface, the cost of the prefix, and so on. The FIB is really a distilled table which holds only the necessary information to forward the packets. Such as the prefix, the mask, the outgoing interface, and the next stop IP address. That’s all which is needed to forward an incoming IP packet. So, this FIB table or CEF table is used to forward incoming IP packets. As we can see here on this LSR, if an IP packet comes in, it could be going out as an IP packet but it could also be going out as a label packet. That’s why this FIB table is in-housed so that we can find outgoing label information for the particular prefix after doing an IP lookup. Now we also have this new table, which is the LFIB table. This is a table used to forward incoming label packets.