How Does MPLS conserve the routing table

dppagcdppagc Member Posts: 293
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_collisionlate_collision Member Posts: 146
    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.
  • networker050184networker050184 Mod Posts: 11,962 Mod
    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.
    An expert is a man who has made all the mistakes which can be made.
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