Backdoor

The network backdoor command is configured under the address family configuration mode for the remote end-subnet

R8#

router bgp

address-family ipv4 unicast

network 172.10.0.0/16 backdoor

After the network backdoor command is used in R8, the administrative distance of eBGP(AD=20) is changed to 200 and the preferred path will be via the direct connection between R7 and R8