DMVPN (Dynamic Multipoint VPN) Introduced by Cisco in late 2000 is a routing technology you can use to build a VPN network with multiple sites (spokes) without having to statically configure all devices. It’s a “hub and spoke” network, where the spok...

 DMVPN (Dynamic Multipoint VPN) Introduced by Cisco in late 2000 is a routing technology you can use to build a VPN network with multiple sites (spokes) without having to statically configure all devices. It’s a “hub and spoke” network, where the spo...

Generic Routing Encapsulation (GRE) is a network tunneling protocol developed by Cisco Systems that can encapsulate a wide variety of network layer protocols inside virtual point-to-point links or point-to-multipoint links over an Internet Protocol n...

BGP has a simple loop prevention mechanism for external BGP. When you see your own Autonomous system number in the AS path, we do not accept the prefix. This mechanism is fine for Internet routing but there are some other scenarios where this might b...

 OSPF Sham Links are required when we try to use a backdoor link between two CE routers in MPLS VPN PE CE scenarios.   What is OSPF sham link ?OSPF Sham links is a logical inter-area link carried by the super backbone. A Sham links is required only b...