NHRP and NBMA networks
An NBMA network connects multiple hosts, but has no broadcast or multicast capability; data is transmitted only from one device to one other device. For full connectivity in such a network, connections must be meshed in some way.
A full mesh of connections is difficult to scale, so NBMA networks often employ some version of a hub-and-spoke network to reduce the complexity of the network. However, hub-and-spoke networks have challenges of their own.
- The hub becomes a single point of failure for the network.
- All network traffic passes through the hub, which becomes a processing bottleneck.
NHRP allows you to reduce the number of paths through the network and reduces the need for static configuration, helping provide the connectivity of a full mesh but greater scalability.