Hello @CiscoPurpleBelt ,
iBGP and MP iBGP uses are becoming the fundamental block for a lot of features:
OSPF or IS-IS must provide inter loopback routing.
All L2 or L3 services can be signaled by iBGP or MP iBGP ( multi protocol BGP)
a) MPLS base with MPLS iBGP next-hop = MPLS Label switched path with destination remote PE.
b) MPLS service: L3 VPN here two MPLS labels are used in the forwarding plane the external that change at each router hop is provided by LDP or RSVP TE (in first case the IGP best path is used)
c) MPLS Layer 2 services:
c1: EoMPLS LDP based point to point service based on LDP targeted sessions ( the internal label or VC label must be the same on both ends ( Luca Martini's encapsulation)
c2: VPLS with manual pseudowire using Martini encapsulation ( cisco and others)
c3: VPLS with LDP with MP iBGP autodiscovery (cisco , ALU, Juniper) I have used it for a customer
c4: VPLS with MP BGP and MP i BGP autodiscovery (draft Kompella first Juniper then supported also by cisco and other vendords
c5: Hierarchical VPLS ( allows to create a MEF E-LAN service with two types of PE nodes ( i have used it for a customer)
d) NG L2 VPN
EVPN ( derived from multicast NG VPN). EVPN is an evolution of VPLS, H-VPLS that allows to interconnect multiple data centers.
e) NG L3 multicast VPN ( deployed first by Juniper using RSVP TE p2mp LSPs, later Cisco supports it using mLDP instead of RSTP TE p2mp I deployed the Juniper version in a customer)
f) 6 PE over MPLS to connect IPv6 islands over an IPv4 + MPLS + MP IBGP backbone.
6 VPE over MPLS introduces VRFs for IPv6 -> change in configuration vrf definition with two AFs
h) segment routing over IP4 it is again based on MP BGP + MPLS + IP4 LDP
h2) segment routing over IPv6 ( I have seen this mentioned by @harold ritter in Service provider section)
k) seamless MPLS for mobile operators to achieve the greatest scalability. (sort of Carrier supporting Carrier in a mobile operator callled onion model).
For service providers financial institutions like banks these features can become important.Also for streaming sport events.
Hope to help
Giuseppe
