DMVPN - Phase 2 BGP peerings
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.