HUB
interface Tunnel10
ip address 10.1.1.1 255.255.255.0
no ip redirects
ip nhrp network-id 10
tunnel source x.x.x.x
tunnel mode gre multipoint

router bgp 1
bgp log-neighbor-changes
bgp listen range 10.1.1.0/24 peer-group iBGP
neighbor iBGP peer-group
neighbor iBGP remote-as 1
address-family ipv4
network x.x.x.x mask x.x.x.x  < lan network>
neighbor iBGP activate
neighbor iBGP route-reflector-client
exit-address-family


(optional default route)

ip prefix-list default-route permit 0.0.0.0/0
route-map default_rm
match ip address prefix-list default-route


router bgp 1
address-family ipv4
neighbor iBGP default-originate
neighbor iBGP route-map default_rm out




spoke
interface Tunnel10
ip address 10.1.1.2 255.255.255.0
no ip redirects
ip nhrp network-id 10
tunnel source x.x.x.x
tunnel mode gre multipoint

router bgp 1
network x.x.x.x mask x.x.x.x  < lan network>
neighbor 10.1.1.1 remote-as 1
neighbor 10.1.1.1 allowas-in