How Does MPLS conserve the routing table

dppagc

I understand that it has to look at the next hop address to see where to forward the next hop labels or something like that.

I know that VRF is to separate the routing table for different customers.
VPNv4 is IPv4 + RD used to separate different private ipv4 address
BGP is used to transport VPNv4 since it is multiple protocol.

late_collision

I am pretty new to MPLS, but my take on it is this:

MPLS minimizes the routing table on P devices, PE devices still need to be beefy and contain all of the routes. This allows you to buy fewer expensive PE devices and save a few bucks on P devices, since they wont need to be as robust. Other benefits, as the name implies, is the ability to send multiple protocols (IPv4, IPv6, etc) across the network, even if the P devices don't support the protocol. You would run an IGP between all PE and P devices, a set of labels are created and distributed for your internal paths, and then your EGP routes target PE devices as the next hop.

networker050184

When a router is just swapping labels it doesn't need the actual destination in the routing table. You can lower your P routing table from 500,000+ routes to how ever many labeled destinations you have which if you have your IGP set up correctly should be fairly small in comparison. TCAM is what costs a lot of money in routers.