DMVPN - Phase 2 BGP peerings
Unlike OSPF and EIGRP, in a DMVPN Phase 2 arrangement, it is possible to create BGP peerings between spoke routers.
OSFP neighbors and EIGRP neighbors are not possible between spoke routers in a DMVPN Phase 2 environment. However, unlike OSPF and EIGRP, BGP uses TCP connections to the specific network address of the neighbor to create its adjacencies. DMVPN Phase 2 supports such direct communication implicitly, so there is no restriction to the creation of such peerings. This applies for both eBGP and iBGP.
Links:
https://forum.networklessons.com/t/dmvpn-phase-2-bgp-routing/1310/14?u=lagapides
https://networklessons.com/cisco/ccie-routing-switching/dmvpn-phase-2-bgp-routing