What is BGP Backdoor? How to configure BGP Backdoor? BGP backdoor it’s a well-known feature of the BGP which is used to change the AD (administrative distance) of eBGP. By default, external BGP (eBGP) has an administrative distance value of 20 with the help of a backdoor command you can set 200 AD. If two routing protocols provide route information for the same destination the administrative distance is the first criterion that a router uses to determine which routing protocol to use for the best path. The lowest AD value is a more reliable protocol and link. Why do we need to change eBGP AD? Whenever our router learns about a network (prefix) through eBGP and also with an IGP protocol like OSPF EIGRP or RIP then our router always chooses the Ebgp route because Ebgp uses an administrative distance value of 20 so our router by default prefers eBGP over EIGRP AD 90, RIP AD 120, OSPF AD 110. Free Tutorials Theories and Labs 1. Complete CCNA CCNP and CCIE 2. CCIE LABs 3. MPLS full course 4. DMVPN 5. QoS 6. IPSec Social media linkdin: twitter: Instagram: Facebook : #cisco #ciscogateway #cisconetworking #ciscosecure #ciscosecurity #ciscocertification #ciscopartners #ciscocert #ccna #ccnacertification #ccnatraining #networksecurity #bgproducts #networkengineer #networkadministration #ccie #ccna #ccnp #networkinfrastructure #internetprotocol